Has AI really atrophied their tech skills that much?

These people never had any skill to begin with. They only have a codebase now because of AI.

You /could/ do this if you wanted to install Windows 10.

You can still download Windows 10 directly from Microsoft: https://www.microsoft.com/de-de/software-download/windows10ISO

A quality disc can last 10 years or more. At a company I used to work at the backups were burned to discs coated with gold. They had 15 year old discs that still worked.

the guy who designed it is stuck somewhere 10-20 years in the past.

Well, using containerization for everything is very 2015-ish.