Simple, M&M 6 is like the witcher 3, some huge maps not linked between them. Same thing in baldur's gate except the map are little.
Compare M&M3 and M&M6, you will understand.
M&M6,7,8,9 are not open world.
If you want more details in my explanation I can in french because my english is too poor to explain more in details.
In lands of lore, there is respawn in some maps but it is justifiy. If you destroy the nest, no repawns.
I don't remember the name of map.
Okay, I know what you mean. By not open world I thought you meant the game was linear, when you meant that you don't like how MM6 is broken up into smaller maps that you travel between.
Then again, I would point out that MM3's maps are broken into sectors too, although it is instant to travel between them. It is kind of funny though how you can run away from enemies right by you by going to a different sector, and they can't follow you.
At the time of M&M3, technlogoy can explain why monsters disappear between different sectors. It was normal.
Although, it's was a true openworld because you can explore 100% of the map.
In M&M6, only some parts of map are available. It's wihy it's not an open world for me or a cut open world if you want. in M&M7, 8 and 9 it was worst (in m&m9 maps are little).
Might and Magic all had respawns. Even Clouds of Xeen - if you leave some town without killing "boss", it will repopulate, try it with Vertigo.
Visit town without killing boss during very long time is very strange in M&M 4 because city are not difficult.
It's more logical to have respwan if you don't kill boss. In M&M6 you can kill boss and alla ennemys, 6 months after, all ennemies respwan. It's just a bad design.
I didn't play Strahd's Possession, but people say it also has partial respawn.
I have finished three times and never seen any respwan.
Baldur's Gate had respawns. All over the place.
Like in stonekeep, I have finished this game many times and I have never seen rrespwan.