The guy sounded seriously mentally unwell. Maybe if we had better support for mental illness and less stigma around the whole issue, the outcome would have been different. But I find it hard to put blame for his suicide on the people who didn't want to be associated with him after his despicable behavior became known.
The other thing is, the accusation (it was a single one in fact) was flimsy, the accusar have accused a lot of other people over the years and made some weird claims (like claiming she murdered a person in an alleyway)
I said twitter mob because it was a twitter mob, literally, outsied twitter he was not that bashed, it was only on twitter that there was a huge storm of people bashing him, mostly people that weren't going to buy his game in first place.
But in a general sense I don't see why you assume that the "mob" are not customers or fans. How does "cancel culture" even work if the actual customers and fans maintain the same level of sales? What is the mechanism by which public pressure causes a "mob" to exert control over a company's decisions?
The guys who made Kingdom Come Deliverance were pretty outspoken and brash, and got a -lot- of heat. The game still did fairly well.