But they are the people who least need to optimize their routines towards muscle gains. Any remotely sensible routine will get them huge gains if they stick to it.

Beginners need to optimize for a routine that they can consistently follow, not for the most effective exercises.

That's my entire point. if beginners think they need to do huge sessions, that can be intimidating for some.

This research is confirming "just put _some_ effort in consistently", which is basically what you said.