Withdrawing a service is very different from delivering a malignant service. McDonalds is withdrawing from Russia instead of serving contaminated Burgers.
Regardless of multi-cloud deployment preferences, multi-cloud readiness has tremendous value in itself.
Biggest of the values is having the freedom and choice to pack up from one cloud and go to another at the drop of hat.
Another equally important reason is to provide some commoditization of cloud providers so they don't grow all powerful.
It also keeps cloud market open for new entrants that can come in with better/different value propositions than the existing players and stand a fighting chance of playing upon merits.
Unless you (as in general developer and not you specifically) want cloud providers to become massive rent seeking institutions, keep optionality in the ecosystem.