Also, you clearly have not written software using Node.js on a long enough time horizon. Pinned versions don't mean anything when sub-dependencies can have transient versioning resolution occur.
The reality is that unless you can fully byte-for-byte assure what you have deployed today is what you can retrieve from an old tag, let's say weeks, months, or years from now, you don't have a replicable build.
Most people will never need to do this, sure, but serious operations who will choose Node.js to build some software and then plan to walk away from it later should not only commit their node_modules directory, but also keep a copy of the designated Node.js engine version as well. It's not likely you'll need a backup of an LTS version when you can just go retrieve it, but that's not the point:
You will encounter a scenario in your professional career where retrieval is not an option for some piece of software.
Edit: There are industries where committing prebuilts is normal and has absolute strengths, and having experienced it myself, it certainly is desirable sometimes.