We want more than this world can provide - we want the best that we can imagine.
Of course, some people don't have much facility for imagination - yet at the very least, we want what this world cannot sustain. This would be Paradise - the best things of this world (or, the feelings induced by the best things of this world), sustained; Paradise is engineered as a place of happiness - but it would not be Heaven.
Some people most want very evil things - power, domination, destruction, to see others suffer - to themselves be the cause of suffering, to take pleasure from the suffering they have inflicted... and so on. Paradise for such people would be a place dedicated to their own satisfactions (therefore indifferent to others) - it would not be any kind of Heaven.
Heaven is for divine beings - can we imagine ourselves as divine, yet still our-selves; can we imagine life in a world of similar divine beings? in general - we need help in imagining Heaven, whereas Paradise comes naturally and spontaneously.
Indeed, Paradise does not need to be imagined - because we already know what it is like; all we have to suppose is that it is like the best things that we have felt, and sustained - this does not need imagination, it is merely an extrapolation.
Heaven does require imagination, indeed in mortal life Heaven could be said to exist only in imagination. This is not to say Heaven is 'imaginary' and false - but that imagination is the primary reality - and if Heaven cannot be imagined, then it does not exist during our mortal lives.
We need help in imagining Heaven, and if we do imagine it, we may not be able to communicate that knowledge - because the task is to induce that imagination we have experienced in the mind of another person. Speaking of our imagined Heaven, or writing it down, or painting it - does not necessarily do this - indeed it may induce some quite different and false imagination in another person.
Nonetheless, communication of imagination can happen, and imagination is the place where knowledge of Heaven exists (and no other place) - and I think perhaps more people lack this knowledge, and need this knowledge, more urgently than ever - so Heaven is something that needs experiencing and communicating, if at all possible; and this has to be by imagination - with imagination taken seriously, and imagination recognized as knowledge.
People who can imagine, and can imagine Heaven have a job to do. They can only do half the job - but that half, they should be doing.
Note: Imagined depictions of Heaven which have helped me include from Tolkien the Undying Lands, Rivendell, Lothlorien and the afterlife in Leaf by Niggle; from CS Lewis the end of The Last Battle, the end of The Screwtape Letters, and most of The Great Divorce, from Joseph Smith the King Follett Discourse, and from William Arkle his Letter from a Father.