What's the purpose of the physics tag? Every question is supposed to be about physics.
I've tried removing some myself but new users keep using it.
There is indeed some room for debate on whether all questions on this site must absolutely be about physics, or whether some non-physics astronomy questions are a good fit here. But this debate is irrelevant: questions on this site do not have to specify that they're about physics. The tag conveys no information.
Further, it leaves the option for new users to use only that tag, e.g. this question. Chances are, if no other tag applies, that the question is off-topic here. The existence of the physics tag makes that less evident.