Rest days have really helped a ton mentally actually. I used to never be consistent with any sort of workouts I tried. Because I tried to do them daily and then would just soon get tired of doing it and stop altogether. But now my goal is 1-2 days between workouts. I've been able to be fairly consistent since March of this year...excluding unusual things like holidays and illness. I've never been this consistent for this long and I think the rest days are really what helped make the distance. Instead of dreading it every single day, I can mentally prepare in advance for when I have to go versus when I can just chillax and veg on the couch.
"i gotta work out -> I'll do it daily! -> oh no i missed one day -> might as well give up"
When in reality going once a week is better than not going at all. Going three times a week is difficult enough, especially when you have other responsibilities or hobbies.