I'm typing this on an old macbook pro running linux. I'm not aware of face id being required for anything yet, but that is definitely the direction apple (and everyone else) is going. If you are familiar with macOS I would recommend trying out Ubuntu.

It's pretty easy to create a live dvd or make a bootable USB drive and give linux a test drive without making any permanent changes to your computer.

If you decide you really like linux you can install it fully from the live dvd or usb drive.

No need to swap hard drives, but that's pretty easy too. All you need is a phillips head screwdriver (and maybe a torx driver). ifixit.com has tons of crowd sourced instructions and how-to videos.