I think the very fact that so much emphasis is put on boundaries in therapy is both a) indicative of how infantalizing it can be (with the therapist putting in firm rules and explaining them much like you would to a small child) and b) strong evidence for how much power they have.

There's no other relationship where you'd tolerate someone having this many 'boundaries'. In fact, if anyone acted like a therapist did, you'd probably recommend they get therapy! Therapists actually act like prize weirdos most of the time.

I think boundaries are mostly there to keep the therapist sane and separate from clients, and have very little to do with the client's well-being. I think some therapists frame the boundaries as if they're for the client, but I think that a disingenuous lie. For example, the reason why your therapist won't answer ten emails a day isn't because it's bad for you. (It might actually be really therapeutic and useful for you.)It's because they don't have time to do that and trying to would drive them insane. If they were up front about that as a logistical reason for not replying, that would be fine. But framing it as being a 'boundary' there for the 'client' is just nonsense.