There are many forms of power in the world. If you think of geopolitics purely in terms of money, you miss all the others, and then it still costs you money.

Which is not to say money doesn't do anything, it does, it's just that one of the others is "reputation", and everyone who signed up to the Budapest Memorandum on Security Assurances and then ignored it or weaselled out of it, damaged their own reputation. Russia moreso than the USA, obviously, but even the USA being unconcerned about this will make it very much harder if the conditions rhyme in future and someone else is expected to give up nukes in exchange for a "Security Assurance".

A damaged reputation makes it more expensive to get other things you may want; from everyone, even the non-involved.

They're unwilling modern battlefield tactics tester and actually losing the Ukraine to Russia would be a pretty big blow to the Europe and to the lesser extent to NATO.

Its not like the rest of the world is not getting anything from Ukrainians standing up to the genocidal KGB* apparatchik.

*yes, i know, FSB. Same organisation really.