This problem does happen, but committing node_modules won't fix it. Assuming the npm registry doesn't dissapear, npm will download the exact same files you would have committed to your repo. Wherever those files came from, 4 years later you upgraded your OS, and now the install step will fail (in my experience usually because of node-gyp).

Unless you were talking about committing compiled binaries as well, in which case every contributor must be running the same arch/OS/C++ stdlib version/etc. M1 laptops didn't exist 4 years ago. If I'm using an M1 today, how can I stand up this 4 year old app?

The real problem is reproducible builds, and that's not something git can solve.