Monks in D&D are no joke. I've gotten torn up by them before. That class has actually been around since the very beginning. I think I might replay as one.
Interesting, the general consensus in rpg spheres I hang out in is that monks are cool and flavorful but dead last mechanically.
I've never run the numbers myself, or even played a monk, but I can say at higher levels "stunning strike" beginners pretty impossible to pull off with how high enemies con saves all end up being.
The picture I've been getting is that they are considered pretty awful by most 5E experts, but a combination of rules changes, class tweaks and magic items make them much stronger in BG3.
They’re bad unless played a very specific way with some specific gear to help them dig into that niche they fit in. They don’t just do great no matter what like a lot of other classes
The best part about this build is you can build Dex-Wis with just a little Str in the late game. Dump Con, Int and Cha. You can get an amulet to set Con to 23, and chug potions of giant strength for fights you really want to nova. On a regular fight, dex and wis carries you (and maybe a +1 or +2 in Str for a little extra damage). But then you drink a lot to set your Str to 27 and just go nutty with the tavern brawler bonuses.
I've been running a githyanki monk wizard and I love it. I can use medium armor and swords. I'm playing it as like a secret Zerth convert. It's a better gish then eldritch knight or arcane trickster.