It depends on whether you mean protection by primary legislation.
The 1964 Civil Rights Act outlawed discrimination on the grounds of sex, race, colour, national origin or religion. It did not include sexual orientation or gender identity (unsurprisingly) but, in 2020, the Supreme Court ruled that sex should be taken to include gender identity and sexual orientation. So, on paper, that extends the protections to gay and trans people. But the problem is that SC judgements are often chipped away at, by subsequent cases - as happened with Roe v Wade, for example: its scope had been narrowed, years before it was overturned. And, as happened with Roe v Wade, a SC judgement can be completely overturned whereas, once a right is enshrined by primary legislation, it cannot usually be overturned without further primary legislation (at least in theory).
So I think it is reasonable to claim that gay and trans people currently have less secure employment rights than other protected groups, even though they do have the same rights at present.
This is all Federal law. In some states, State law gives protected groups additional employment protections - summary here