Nah at a small scale it's totally fine, and IME pretty pain-free after you've got it running. The biggest pain points are A) It's slow, B) between auth, storage, and CI runners, you have a lot of unavoidable configuration to do, and C) it has a lot of different features so the docs are MASSIVE.

Not really. About average in terms of infrastructure maintenance. Have been running our orgs instance for 5 years or so, half that time with premium and half the time with just the open source version, running on kubernetes... ran it in AWS at first, then migrated to our own infrastructure.

I type docker pull like once a month and that's it.

Uhm no? We have been self-hosting Gitlab for 6 years now with monthly updates and almost zero issues, just apt update && apt upgrade.