Why are therapists not taking insurance??

I’m in the US and I’ve reached out to dozens of therapist and they’re all telling me they aren’t taking insurance.

I’ve never encountered this when trying to find a therapist but it’s been a while. Has something changed that folks aren’t accepting insurance? Regular people can’t afford $200 a session and I’m finding it pretty messed up to expect that people can… unless there’s something I’m not understanding?

EDIT: I’ve learned a lot from all your kind and detailed comments, thank you!