Having done just that -- try again with another therapist (actually several) -- I cannot recommend it. Made things worse.

The assumption is that the problem was with the particular therapy relationship, rather than with the system, which seems specious. So a client who has endured some degree of recapitulation of early attachment trauma (or any significant negative outcome), and is now in an even more vulnerable state, is encouraged to play another round of russian roulette with a total stranger whose own emotional and psychological health is unknown, whose methods will likely be undeclared, who might have trouble properly acknowledging the harm done by the previous therapist thus subtly invalidating said harm, and who is effectively taking the client's money to clean up the mess made by the previous therapist.

No matter what happens in therapy, seems the advice is always… more therapy. What if there is a second round of wounding in therapy? Should the client seek yet another therapist? Can you imagine that conversation?

client: "Yeah, hi, I need help sorting out two levels of therapy retraumatizing, plus the original trauma and some other issues.
therapist: "I see. Well you can trust me. I estimate you will need a minimum of 20 years of therapy."

Maybe the sensible thing to ask is -- was therapy a good idea in the first place?