Sure it is, but the distinction between terrestrial planets and gas giants are also useful, that doesn’t mean the latter aren’t planets.

I think it is fine that there are more objects planets then we can meaningfully count. Loads of things in our language act like that. E.g. a bug can be any number of things, and you know what a bug is by just talking about it. If some insect society then comes up with a meaningful definition of bugs which excludes spiders, that definition isn’t really doing the average user of that word any favor.