Every company I've been at that tried to self-host something like GitLab, later moved to GitHub. Nobody in business cares if it's open source/free software. They care about managed hosting, centralized services, invoicing, etc. DIY is great for hobbyists and the cash-strapped.
This is far from truth imo. It is very possible to only use (F)OSS. Github, AWS, Azure, Vercel are not at all more pleasant or easier to work with than on-prem Gitlab/gitea/codeberg/jenkins/k8s/kibana/prometheus/grafana.
I could spend an hour and have a full setup done on physical or VPS to have 1) remote git hosting 2) pipelines running on changes 3) pipelines publishing images or some artifacts 4) automated deployment for these images/artifacts
I'm struggling to see what am I missing. What is worthwhile that Github offers? It is popular and easy to set up org+repos, but that seems it. A few years ago I was working on Azure Devops with the azure pipeline and that was the worst developer experience I've ever had. AFAIK Github actions uses the same syntax and works the same way, at least it was at that time.
This sounds like a week or two of work to me (I'm a novice though). You should write a guide.