I still don't understand why people want their code dependent on the web. I want to share my one true dev environment, but I want to be able to do this on my p

I still don't understand why people want their code dependent on the web. I want to share my one true dev environment, but I want to be able to do this on my private premises setup without internet access. I don't trust the internet and things like codespaces not to leak my company's code whether nominally in a private repository or not. I don't trust using internet dependencies either. Even something like pair programming etc with a shared view of a project is very appealing, but again, it needs to be appealing in a private context and not dependent on public access. What might be OK for an open source project is unlikely to be true for a company's valuable IP, but people just seem to get carried away. Secure first, managed dependencies first. Please.