It is acknowledged generally that whatever Peter Best may or may not have made up to that point, the release of the Beatles Anthology collection made him a millionaire instantly, from his share of royalties for tracks on which he played.
You cannot really speak of ‘what was done to him’ – because that implies that the rest of the band sacked him because they knew they were going to change the known world forever, and just didn’t want him to have a share of it.
The truth is far more humdrum – they simply wanted a better drummer, and Ringo was a better drummer. What was ‘done to him’ is what happens to bands every day, some musicians don’t cut it for a variety of reasons, and I am sure they accept that fate was not on their side that day. There is little point in wondering what might (or indeed might not) have been.
What about Chris Stewart, John Silver and John Mayhew? Never heard of them? History was far more unkind to them – they were all drummers in Genesis before Phil Collins, and are routinely air-brushed from the band’s history.