depends on what youre going for. but id have to guess for most people, typically not. and i think that might be the biggest misconception about therapy. sometimes you can be cured (like if youre "just depressed you lost you job" but then you get your life straightened back out and youre fine) but for the most part, from my understanding, a lot of people that are going to therapy are neurodivergent people. and that isnt something thats ever going to be "cured" (nor should it really be viewed as something that should be cured). youre going to live with it forever, but therapy (be it with a "professional" or taught to yourself) can give you healthy coping mechanisms which a lot of people are missing because most dont know how to handle someone thats neurodivergent so its hard to teach your child what you dont know (plus abuse).
so no, most people dont get "cured" and its something you typically have to do until you die, but it typically becomes a normal part of life the more you practice it, so its not as heavy as that sounds.
therapy can be helpful, but like everything else in life, its person depended. are you in the right state of mind for it. i know through my recovery my thoughts towards things have changed depending on where im at. but theres also the question of 'is this the therapy i need'. its like a physical illness (but worse). if you have an infection, i can give you an advil but its not going to do anything. you need the right medicine you need an antibiotic. its the same idea with mental health (therapy or medications) but the difference between mental and physical is for the most part all physical problems can be treated the same. however with mental everyone has a unique chemical make up and different problems (that even could have brought them to the same issue). and that makes it really difficult to treat and part of the reason you will see some people praising medication/therapy and others saying it needs to be taken down. (its needs adjustments)
my over all point is, there isnt really an answer to your questions. its extremely person dependent.