The idea of a rest day is flawed in my opinion, because you don’t need a day to sit and do nothing.

Given how fundamentally you appear to misunderstand the term/concept of a "rest day", I'm not so sure you should be broadcasting your silly opinion with such confidence.

A Rest Day does NOT mean sitting in bed all day. It means a day of recovery. The most elite athletes and trainers in the world endorse the concept.

This should help the next time you want to contribute to a similar discussion: https://www.uclahealth.org/news/how-often-should-you-take-rest-day