Betts did not play on May 5 and June 14. He did not start games on April 7 or August 11, though he came in late in the game. So basically, he’s not starting 1 game a month.
Bogaerts did not play on April 3, May 1, May 26, July 6 and August 6. He’s had no games where he came in late. Again, about once a month.
Devers did not play on May 24, June 9, June 23 and August 10. He did not start April 4, April 23 (Game 1), June 21 and June 22. He came out after 5 innings on June 19 and the Sox had an off day on June 20, so the June 19-23 games are when he had his hamstring issue. He also wasn’t exactly crushing it in April, so a couple of those early ones may have been matchups.
Beni has sat out a few games vs. southpaws and they kept him out of the lineup several times around the All-Star break when he was in a total funk at the plate. It worked.
Bottom line is “rest” days have about once a month. Some of the other games off were for matchups and injuries. It’s not like they are getting one day off a week.
And if you look back at the “old” days, when you think guys never had a day off, you’ll find very few players who even played 162 games, much less started that many. Most were in the 150s played, and less than that started. And yes, I am aware there are exceptions.