Can you elaborate? Her channel seems to be about science, it's common that science popularizers discuss science outside of their field of expertise...

Science is a large field. Being an expert in physics won't make you an expert in other scientific fields, yet somehow people love to know the opinion of their favourite heroes of any topic.

Remind me of Jurgen Klopp rebuking some journos that wanted his opinion, as successful football coach, on COVID.

Just the field of physics is so large that most would probably not dare to state criticism in other sub fields. Like a Nobel prize winner in solid state physics would never judge the work of a high energy particle physicist and vice versa.

Hossenfelder is definitely qualified to talk about the OP, but her videos about transgender people shouldn't be given more credit than videos from almost any other person.

There is definitely value in people popularizing scientific consensus even when they aren't experts in the field, Bill Nye talking about climate change is useful even though he's not an expert. But when you aren't an expert and aren't trying to convey the consensus of people who are experts, you're Just Some Person With An Opinion.

It's when a popularizer starts having opinions that aren't widely shared in a field that they aren't themselves expert in that things can start to go wrong.

Being publicly contrarian about stuff you're an expert in can be interesting, being publicly contrarian about stuff you just don't know much about is at best not very useful and at worst harmful.