The only time using UTC breaks down is when any sort of time change gets involved.
If I say I want a reminder at 9am six months from now and you store that as UTC, a day light savings change will mean I get my reminder an hour early or late depending on where in the world I am
It depends on the application.
I don’t remember all the specifics but this is the blog post I refer to when this topic comes up
https://codeblog.jonskeet.uk/2019/03/27/storing-utc-is-not-a-silver-bullet/