I've been seeing a T for over 15 yrs now. Both T's have the mind set that everyone can benefit from therapy, and there is no time limit. The only thing that they have suggested is adjusting the length of time between sessions according to how things are going. Certainly, they have clients for 5 to 15 sessions and then that's it, done. They have a specific issue...over and out. For clients like me with recurring bouts of depression (varying degrees) and terrible anxieties (due to early childhood traumas), issues keep arising that become too overwhelming. I have taken "breaks" where we space our sessions out 4 weeks or so, but when needed, I go back every week or every 2 weeks for a while to get back on track.
Current T has a client that's been with her for 20 years. Checks in every year with her, or more often when needed. There should be no shame in that. Life happens and I think having that support there is a good thing.
I think it's the stigma of being in therapy that makes us think it's a bad thing to do it long term.
I understand, however, that I am both lucky and blessed to have a good job and good insurance to be able to afford therapy. Although my job is high stress and I think is a large part of why I can't handle the rest of life...
I am hoping that when I retire I can quit therapy.