That is something most fans don't understand.
Jerry cares more about being in front of cameras and microphones where he's always eager to share his opinions on everything team related.
I think he stopped making solo decision for the team long ago, but he keeps himself front-and-center in interviews so that if the Cowboys one day win a Super Bowl he can still take full credit for it.
He's got a good balance these days. Still jumps in sometimes on moves that are probably forced like Kellen Moore or Jason Garrett as OC, or pulling the trigger on the Trey Lance offer.
He's the GM, he has the right to do all of that. In that position though, I would think you should always be careful about the impression or feel of 'undermining' since he is also the owner. Extremely easy for Jerry to out alpha dawg a lesser coach.
I think the last time Jerry could have been described as meddlesome though was during the last Jimmy years when he wanted to bring celebrities on sidelines, take credit in media for Jimmy trades, and all the other complaints we heard from the Jimster. Mainly because he wasn't really the GM yet, Jimmy ran a lot of the football ops. Some Jimmy's fault, some Jerry's fault. Two big egos that as Aikman said, should have realized they were in a once-in-a-lifetime dynasty, put aside their differences for the sake of the team, and kept it rolling.
The later moves, like pulling triggers for franchise WRs and giving away too many picks, bad signings, bad draft picks.... that's all on GM Jerry. He has the right to fail as much as he does succeed. Just feels like there is a balance now and Stephen, Will, Mac, DQ, and everyone involved gets a say and can stop nonsense.