It is huge operation keep afloat by a few people
Exactly what I regret paying for. Obviously they're in over their head.
I don't mind paying for a service. In fact, I believe in paying for what I use so much that it's the very reason I chose to open an account with SDF to take my first steps on the Fediverse rather than open free accounts on bigger servers. But I do have a problem when whatever I paid for chronically doesn't work properly. Had I been told SDF was understaffed and underfunded, I would have sought to pay for the same services from someone else - or even host my own instances.
I understand what you're saying, SDF's raison d'etre and philosophy totally resonates with my own set of values, and I sympathize with their staff. But the fact remains that I regularly spend 10 minutes posting something that disappears in the ether because some stupid bug no other (free) Lemmy instances seem to have doesn't get fixed on the one instance I really really want to support.
After like the 5th time, and with the other problems I have, it gets to be supremely frustrating.
It's not the money. If SDF asked me 10x the amount I paid, and do so yearly, I would still pay it for basic, fully functional services. It's the really nasty feeling of trying to do the right thing and getting less than everybody else for my goodwill.