For most roles, severance is not a guarantee and only given as part of layoffs because companies that don't are crucified.

I.e. getting fired/quitting will not trigger some severance clause for nearly all employees, even constructive dismissal.

The reddit gold model didn't work. Reddit was a VC funded start up though, so if was expected to make a lot more than just enough to keep the servers going.

I'd bet lemmy instances can get by on donations and reddit style awards. Like you say, it can be incentivized further with cosmetic rewards.