Gitlab in particular is unbelievably easy to self host. At my last gig I ran it on a t4g Debian instance with unattended upgrades and then just rebooted once a week at like 3am, literally never touched it again and it costs nothing to run.
(Also, when upgrading GitLab, make sure to upgrade version-by-version and always wait for background migrations to finish before upgrading to the next version. You can check background migrations at /admin/background_migrations.)
To be fair though I'm using docker and watchtowerr to keep it updated, there was 1 time where I had to use an older docker image because the latest wasn't working.
Not unrecoverable though, so saying you need to worry about it may be a bit too alarmist.