Words don't just have a literal, technical meaning. If the phone itself doesn't allow a straightforward, user friendly happy-path for removal, it might as well be "unremovable" in a sense that it is indeed unremovable for most users. "adb shell etc" implies that one has a PC with this tool correctly installed, and many people don't even have a PC in the first place. Then comes the case of installing adb, setting it up correctly, and having a cable to connect the two, enabling debug mode, and doing the thing. This is much more like a service thing, than a do it yourself at home thing. Not much unlike "chip tuning" for cars.

The article claims the app can only be removed with root access, which requires more difficult and technical steps to attain than running an adb command. If uninstalling the app with adb works and doesn't result in the app being promptly reinstalled, then the article has a significant factual error.

This doesn't strictly require a PC. There's this trick with using the wireless debugging feature to connect the phone to itself. You can do it with a terminal app like Termux but Shizuku is a nice GUI that streamlines this process and exposes an API for other apps to use. After a quick web search I found https://github.com/samolego/Canta which is, again, a GUI app that uses Shizuku to uninstall apps via adb.

I agree that it's not easy, but anyone sufficiently annoyed by these non-otherwise-removable apps who is able to follow instructions should be able to get it done without needing a computer or special knowledge or messing with the command line.