I agree. However, I also think that a lot of the world, especially Europe, has a strange and unrealistic vision of what a multi-polar world would look like. A multi-polar world looks like 18th and 19th century Europe writ large, with nation states jockeying for power, and war being considered as a logical extension of economic and political policy. It isn't nations coming together and negotiating peacefully at the EU or UN or wherever.

It feels a bit like the U.S. thinks the rest of the world isn't capable of looking after itself.

Arguably because the rest of the world isn't. If you look at the "free world", who actually spends even 1% of their GDP on defense? Heck, half of Germany's air force can't even fly because they've pared their maintenance budgets back too far to buy spare parts for their planes. When France and Italy bombed Libya, they had to rely on the US to provide necessary logistical support, like tankers and reconnaissance, and even the smartbombs themselves. Taiwan explicitly relies on US carriers to guarantee its territorial sovereignty against Chinese aggression. Japan likewise.

A world in which the US is in full retreat is not a more liberal, peaceful world. It's a world in which even more autocratic powers, like China and Russia advance.

EDIT: By the way, I totally agree that the US is overstretched. But unilateral retreat, leaving our allies in the lurch to face hostile powers on their own is not the correct way of addressing that problem.