In particular, GPU availability has been a continuing problem. Unlike interchangeable x64 / arm64 instances with some adjustments based on the new core and ram count... if no GPU instances are available then I simply cannot run the job. AMD's improved support has increasingly provided an alternative in some situations but the problem persists.
I recommend doing the work to make the business somewhat cloud agnostic, or at the very least multi-region capable. I realize this is not an option for some services that have no equivalent on other clouds but you mentioned databases and k8s clusters which are both supported elsewhere.