The short version of the story is that I used a mess of tooling to get a KeePass-based workflow going, and it resulted in data loss that I had to recover.
I stored my database on a cloud storage provider, and then I would read that database with various clients on my various platforms. At that time, just about none of the (good) clients were cross-platform (KeePassXC that you brought up has no mobile apps).
At that time, an open-source Mac client had a bug that caused some extra fields to be cleared/not saved. I put some important information in those notes and they were lost due to this one client being buggy. Luckily, my cloud provider kept a backup of previous database files.
That's when I realized that having someone else manage all this was way better than saving a few bucks.
I've used 1Password through a lot of new version changes and complete rewrites and I can't recommend it enough. It integrates deeply with all my devices, supports the latest developer frameworks on those devices (e.g., delivering a Safari for iOS extension as soon as extensions were added to iOS), and it's packed full of features that I never dreamed of having with KeePass.
This optional opt-in telemetry seems way more reasonable and respectful than comparable SaaS services and commercial applications, but, alas, "telemetry" is a boogie-man word. Maybe that KeePass app that dropped my data could have used some telemetry to spot that error a bit faster.