Genuine question, why not use a free Git service or something
I pay for Sourcehut now, but until recently I was using a free private GitHub account to sync my notes in Obsidian. It works fine and cost me nothing (at least nominally).
The honest answer is because I backup a large number of other things to backblaze anyways.
I went on a mission about 5 years ago to essentially stop paying for SaaS services if there was an opensource alternative available that I could self host.
I have old machines lying around anyways since I was upgrading about every 5 years for gaming. So I have a 5 node k8s cluster in my basement serving about 20 different services that I use, and I no longer pay for basically any subscription software.
Git is fine for text content, (hell, I have about 25 personal repos on github anyways, although speaking of... most are mirrored to a local gitea instance) but it's not a great solution for backing up DBs, binary data, media, photos, etc...
Eventually - I'll likely replace backblaze with a NAS at a family member's house, but for now - it's very cheap and the billing is fair (usage based billing, not the exorbitant monthly fees most SaaS services charge).
---
Plus - I really like the flexibility of web based services. I don't have to remember to sync anything with bookstack, I just hit 'https://bookstack.[mydomain]' in a browser from any machine I want - Friends house? works. Public library? works. Wife's phone? works. Work laptop? works. etc... you get the idea.
Even after accounting for the initial outlay for a large NAS and my extra power consumption - I broke even in just under 3 years self hosting. Turns out SaaS is sorta a scam if you're technically capable.
And absolutely more power to ya for finding your own alternative solution!
I pay for Sourcehut now, but until recently I was using a free private GitHub account to sync my notes in Obsidian. It works fine and cost me nothing (at least nominally).