This seems like a very niche situation. To get to a 20-ish DC on stunning strike we are talking about probably a 20th level monk (you need at least a 22 Wisdom). Monks always prioritize dexterity and are a famously MAD class, so their DC is typically quite low. For example, my level 8 monk's DC is 14, and this strikes me as pretty standard. So that's a vanishly small subset of monks, and given all the other stuff that monks and everyone else can do at level 20...eh. Not that impressive. I would say the monk's five attacks every round, not to mention insane maneuverability and resistance to basically all damage, are a lot more impressive. You can take stunning strike away completely and most opponents are still completely screwed against a level 20 monk with the 2024 rules.
I love the nerf to stunning strike. Spamming it turned monks into one trick ponies, and the new version actually produces a useful effect even on a successful save. I use stunning strike very, very rarely. I use grapple every round, at no loss of damage or resource cost, unless the larget is too big.