Last and First Men

Successive human species reach full automation, several times over two billion years.

It depends which species. Some decay into aimless pleasure once the machines carry everything. Others invent religions of work, or of movement, or of flight, specifically to have something to organise a life around.

Enforced idleness — Everything is provided, so nothing is left to do — and that turns out to be unbearable.

Not a novel so much as a future history. Stapledon runs the experiment repeatedly and gets a different answer each time, which is more honest than anyone since.