Any such term, including 'racist' and 'sexist' can obviously be tactically misused by stating that someone's behavior or words were racist or sexist (or homophobic and so on) when they weren't. The misuse can give someone a lot of power if others in the same group fear being labeled and are willing to shut up and let the accuser dominate the conversation.

I see 'transphobic' used online almost always this way, i.e., as a debate stopper, though I read about real transphobia in the news and elsewhere (violence, harassment and so on). I think that now it is fair to say that anything except complete compliance with any demands a trans activist makes, however extreme, will be labeled and treated as transphobia.

Oddly enough, I really don't see 'sexist' and 'racist' misused that much! Some, yes, but not like 99% of all uses.

TERF is used in an even worse way: It's the Scarlet Letter stamped on someone's forehead, and everything that person then says will be met with threats. And nobody bothers to even find out what is so horrible about being a TERF because the term and its meaning are entirely created by the most fervent trans activists.

"Islamophobia" is another term which is sometimes used tactically to stop any criticism of the religion, Islam. Its use should be limited to discussions of anti-Muslim bigotry, because it would be terrible if there was only one religion we cannot question or criticize at all. Criticizing the misogyny in religions is what feminists do, and it is important work and not at all phobic. Most religions have parts in their holy books which legitimately frighten women, and discussing those parts is not phobic but realistic and important feminists work.

I think this is similar to what is happening with trans activism. Nobody is allowed to criticize their religious dogma at all, even if that criticism is only about theoretical concepts and not about transgender individuals.