There is a very funny novel by Michael Frayn called The Tin Men (1965) - set in a computer establishment where one of the characters is attempting to construct a 'Samaritan' robot that is 'altruistic'; such that it will willingly sacrifice its own existence for others.
The background assumption is that self-sacrificing altruism is the highest form of ethical behaviour - and this is indeed probably the mainstream assumption in all modern atheistic leftist societies (which, nowadays, means everywhere).
Considerable humour comes from the problems of programming this robot - in particular the difficulty that when the robot is made to want to sacrifice itself, and seems to get 'satisfaction' from doing so - then this no longer counts as self-sacrifice because it is merely selfishly doing what makes it happy.
The ideal seems to be a robot that will willingly sacrifice itself for others, or at least others who are also moral agents - if that can be detected - but will be made more miserable by doing so...
This is one of many paradoxes and incoherences that come from the common idea that altruism is the highest moral value and the proper guide to living.
One frequent idea is that the greatest public moral exemplars are those who - supposedly - live for the benefit of others despite cost to themselves.
(Or, at least, donate time or money to organizations that claim to facilitate this... hence the structural role of 'charities' in objectively validating the moral-superiority claims of the ruling classes: charitable work 'proves' that these are truly altruistic people who deserve their fame, wealth, power and status.)
But altruism merely kicks the can further down the road; because altruism fails to provide any meaning to life.
If my life is to be devoted to preserving and enhancing the satisfaction of other lives, and if this ethic is general (so that society aims at being composed of people all and always doing stuff for each other - but never for themselves) - then this fails to provide any understanding of what all these other lives are For.
Why is it good for me to 'help others' - help others to do what, exactly?
What ever 'that' is - which altruism is directed towards - must itself surely be the primary reason for living?
(I felt this strongly when I worked as a doctor. The left-liberal altruistic ethic reduces to reducing-suffering in others - since this is regarded as a self-evident Good - so medicine ought to be a perfect exemplar. But it did not feel like that. As I then was I knew of no purpose or meaning in life and denied P & M in the universe; so I found it strange that I was supposed to get maximum life satisfaction from keeping people alive and functional to live lives that they themselves mostly regarded as meaningless, futile and miserable (especially in psychiatric practice). Yet everybody apparently assumed that this 'helping people' was one of the best things about being a doctor, and why I was a doctor.)
Altruism is vacuous as a guide for living.
Yet the nonsensical altruistic ideal persists - especially as the very basis of leftism - which claims to be the ethic of altruism; with society organized on that basis. Leftist ethics nearly all assume that it is the highest duty to live our lives (and donate our taxes) for 'other people' (or, at least, those 'other people' currently defined as worthy by the leftist Establishment).
Leftist governments (ie. all governments) assume total power to monitor and regulate all human lives on the basis that this is necessary to ensure that everybody lives and works primarily for everybody-else - and to do otherwise is selfish and evil. Anyone who fails actively to support the altruistic authorities is thus selfish and evil.
This leftist ethic of altruism is also used to attack Christianity; on the basis that (supposedly) Christians pretend to be more altruistic than anyone else, but are really super-selfish in their desire to sacrifice happiness in this world (including to allow preventable suffering in this world) in return for a promise of a joyous resurrected eternal life in Heaven.
(...Which is, anyway, impossible nonsense - hence merely a feeble excuse for callous indifference to others.)
Perhaps in response, a weird kind of Christianized-altruism (which is not really Christian) sometimes develops; which, if taken seriously, leads quickly to immiseration and death - as shown in the misguided and self-destructive life of George R Price which ended in suicide
Suicide is, indeed, a rational response to the ethic of altruism; since it may be understood as helping others by removing one's own baleful influence, or by ceasing to consume scarce resources...
Indeed, altruism suggests that it may be better never to be born in the first place; so that selfishness is not even a possibility, and others are left with more.
(This is another commonly expressed view - buttressed by the contemporary fake-environmentalism which sees all living Men as undesirable CO2-emitters.)
In sum - altruism amounts to an ethic of self-hatred and death; which is probably sufficient to explain why it is so vigorously propagated by the modern Global Establishment.
It is therefore vital to realize that altruism is not an ultimate ethic, nor indeed a good thing at all if taken as an abstract, general or universal commandment.
By contrast; the Christian morality is based upon love, and focused upon Heaven - which is a place of love: a place that is entered only via an eternal commitment to live by love.
And the reality of Christian love is seen, primarily, in the family; secondarily in marriage; and only much more rarely in friendships with unrelated people. And not all people are capable of love; and some people refuse it.
Which fact means that actual mortal Christian love is partial, i.e. involving particular persons. Mortal love is not universal, nor meant to be - and love may be strongly bound up with the greatest knowable joy, as well as voluntary misery.
"Abstract, universal love" ('of fellow Men' or whatever) is something other and not Christian love; indeed it often (not always) functions as an anti-Christian or indeed Antichrist phenomenon.
A Christian is one who believes that to love and to be loved is the greatest and most important thing in this mortal life (and beyond) - whatever emotions it brings.
But in this mortal life love is usually partial, may be infrequent, and is always temporary because of death.
Thus, the greatest desire of a Christian is that this love we have experienced partially may be made full and eternal...
Which is why Christians want to accept Jesus's offer of resurrected life everlasting in Heaven; where this ideal state of love is realized powerfully and forever. A Christian has decided that he wants this for himself; and hopes that many others will want it too - but especially those people (and other Beings) whom the Christian loves.
(And therefore - in its essence - Christianity has, indeed, nothing to do with altruism.)