I have used github, gitlab and bitbucket etc. Now all of them seems to be training all the code. How do one retain privacy while not paying for enterprise plans?

I know of gitlab offering a self hosted plan, but not really sure if that is worth it and how do we go about it. I am asking for a small team, wherre we don't have dedicated people to manage things like backups, uptime etc manually. we can do it but would ideally see what's the best way. and is there a downside of this approach except for pipelines.