One classic is:
It doesn't seem realistically possible that everybody (or the world, or a certain society etc.) only practises or expresses some (existential) aspects (directly and indirectly, deliberately and non). While leaving the other aspects (from the plural of existential aspects and structural co-existences) unpractised. So that they don't exist in (and with) this particular realm--the world, society, group, structure, etc.
But it seems principally interesting to imagine if such a kind of 'ideal'-direction of expressing some aspects, and others not, would be 'put into practice'. Would be realised or exist--for a certain time or as a constellation etc. For example: The stoic ideal of caring for one's own thought and actions and working on and with them, not the outer situations one cannot control or even tangle in a sense. It's a reasonable concept, expressing some aspects of Existence, in some comprehensible way.
From a pluralistic-realistic view, it's not feasible that everyone adopts/expresses one and the same bundle of aspects. But one can try to imagine a situation where everyone does go this way (or any other life-philosophical, political or life-cultural etc. way). The realisation of an Idealism.
Would--if it was realisable--the world be a better place?