IMO people have a right to be who they want to be
But why? Where did this ridiculous idea come from?
No one has an automatic right to be whatever they want to be. There are many restrictions on what you can be, imposed by physical reality, ability, law, geopolitics, economics and much more.
Yes, it's good to be able to "be yourself" and feel happy with who you are, of course. That doesn't mean you should get to appropriate someone else's identity and experiences, or get to be accepted as a thing just because you want to be that thing or feel like what you imagine it's like to be that thing.
I might want to be/believe myself to be stunningly beautiful, the world's best pole vaulter, 5 foot 2 instead of 5 foot 10, black, blind, a brain surgeon, a man, or 6 years old. But I'm not those things and although I could conceivably become some of them, it wouldn't happen just because I felt it or said it. Reality still exists. If I say I identify as you, does that mean I can come and live in your house? If not why not? If you start saying people should be accepted as a thing they're not just because they say so, everything becomes nonsense.