AFAIK the User ID it's already a plugin so it can be disabled. Ideally, this plugin was disabled by default, or the feature was disabled by default for privacy reasons. This is to prevent any data being recorded without knowing they need to likely ask for consent etc.
Ideally, there is an easier way to enable it though and not just in the plugins manager where it would be barely found. Ideally it would be done in the Admin Privacy section and the user would be educated on how to use it, if they want to use it.