Most therapists will leave their clients during a rupture

I disagree. I don't know if ex-T and I were in a rupture when she terminated me. Maybe? Probably. But she was just one T out of a total of 10. And I've had 8 pdocs all who never terminated with me over a rupture. Though I did terminate one T and one pdoc myself.

I've had a few ruptures with T and L. None have resulted in them wanting/threatening to leave. Quite the opposite. They encouraged me to work through it. And we did and it made us stronger, more resilient.

I disagree with what I bolded. That wasn't my situation -- I am one of the ones whose long-term THERAPIST wasn't able to tolerate the stress of working through ruptures.

But still, the result is the same -- expecting more of a client than they come to therapy with.

I don't know how a therapist might address something like that, if they think that's something they are noticing, besides just letting things slide for the client. But isn't that their job? Or needs to be considered part of their job? Currently, it may well NOT be -- and therapists are getting off the hook because too many clients are not well enough to demand something better.

I am not blaming. I am not shaming. I am NOT saying it has to be either the client of the therapist's fault. I am also NOT commenting on your particular situation or insinuating that you were to blame. But, clients do need to be ready to tolerate the stress of rupture if they are able to stick around to see it through, too. The therapist - as the trained professional - obviously has the onus on them to be able to guide, address and resolve a rupture - but the client also needs to have the stress tolerance to be able to stick around to address it. Obviously not all therapists have the skill or ability to be able to do that, and those therapists do cause enormous harm for the clients.
I know that can read as though I think more is expected of clients. But I don't mean that. Clients are at where clients are at, and unfortunately there are times where clients just aren't ready to tolerate that stress, and no amount of support or intention will change that outcome... because the client is just not ready.
There can be a ton of reasons for that. The client doesn't yet have sufficient self-calming skills. The client doesn't have sufficient support in the their daily life. The client is severely dissociative and doesn't have sufficient internal resources. A million other things. And there are several examples of clients not having the internal resources to tolerate the stress of resolving ruptures right here in this forum.
I am not blaming. This isn't about blame. This is just sometimes the reality of the situation... that the client doesn't *yet* have enough internal resources to tolerate the stress of a rupture in the therapeutic relationship.

Did I say that you were blaming? I don't see that unreasonable expectations on the part of the therapist, or the public, is necessarily blame -- although it could come to that.

I do agree with what you wrote and that I bolded above.