I don't recall when was the last time someone left voluntarily
Probably (or, provably) no one.
keep in mind that most of the time except for a few months (maybe a year at most) the rate was below $6, i.e. BTC was below $8000.
When I applied to this campaign rate was ~$5 and for few months it was, I don't know, around $2.5 (IIRC late 2018. or early 2019.).