In regards to Prolific, I've been on them throughout the years, with their name and platform changes. Very few people get banned incorrectly, from my point of view.
They had a purge of Indian people using VPNs a couple of years ago, and multi-account people last year. They addressed those on Reddit. I've been in several of their Subreddits and communities, and usually the people banned seemed to be the ones who I didn't trust anyways due to exaggerations, etc.
If you lie and answer "I make $140k" on one survey, and then "90k" on the next, or change location frequently etc, your inconsistency will flag you.
Honesty is the best policy!
Edit: Several of the Prolific Team are regularly active on forums, and are very responsive and helpful. They are one of the best companies of this type of platform, for responsiveness, pay, screening, and usability!