Exactly. This is why The Witcher 3 is such a masterclass for open worlds for a few things that the best open worlds have taken and ran with since such as the distance between events on the over world being very calculated to the players time, not too much on the map to get overwhelmed but not to little to loose interest. Assassins Creed copied TW3 for a few games there but failed and missed because of not understanding this philosophy of controlling over clutter and fell so short.
To your point though, There is only two open world game I know that bucks this rule you make early in the OP and that's GTA5 and RDR2, Ghost Of Tsushima also but that has camps that feel very much like dungeons just sat on the overworld with the way they are designed and how you can't access them until a certian point but I do think The Witcher 3 formula is the best, every chunk of of gameplay is enjoyable in different time frames. You can play for 15 minutes and get something out of it or you can play for long sessions, I done near 12 hours days with it and have gameplay loops within gameplay loops all tightly woven together, you go on a quest towards a dungeon on the main path but then on the way there you clear a camp and pick up a side quest and follow that for a bit, do the main quest and then instead of fast traveling back you complete the side quest and turn it in but clear a few monster nest along and have a game of Gwent while grabbing a card for your collection all the while you were gathering materials and gold for your master crafted weapons or stop to see the beautiful sights and explore a new area just to poke around and unlock a fast travel post for later and it all feels like it is part of the main quest even though you could have cut 40 minutes out of the hour by B lining it. It just flows so well.
Now as yo why GTA5 and RDR2 works even though so many that try to copy them like Crack down, Saints row and many others fall so short, I can't figure out. It must be something to do with the way the story is structured into the world and in RDR2s case how everything is so perfectly spaced and feels dyanimc and even though it all is quality it give even more of an impression of excellence as apposed to having loads of markers and clutter. GTA5 I just don't understand but I have played that game five times and it still amazes me but with the world being merely a back drop for the story, I don't get what exactly makes it so enjoyable aside from the fantastic campaign with such varied missions and such detail right down to things like the apartment Trevor occupies showing and not telling the story in between missions and the ever shifting nature of it in that manner, to give the impression that it isn't just some static world but ever changing. I think if The Witvher 4 takes on this level of ever changing detail much like you move around in RDR2 and gives that new Rockstar ever changing world feel whilr also and pulling back even a little more on the map clutter like GoT or Elden Ring has done, it could easily be the best open world game. Right now I'm 50/50 on wheter it's GTA5 or TW3.
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