I´m used to play tactical/strategy maps full of enemies to beat, so I prefer large encounters or tough bosses myself instead of large amount of fights with trash mobs;
When you are playing with rotating shifts the boring fights are the ones that are unlikely to beat your party and it becomes a chore to kill them. It´s better to have challenging, tactical encounters most of the time so you can fully take advantage of all the options (character features, terrain, consumables, spells) you have at your disposal instead of having to kill weak enemies with auto-attack.
Since there´s no respawning in BG3 I assume that´s the optimum way they could go, IMHO.
No reason to fight trash mobs if there´s no respawning or grinding, you can make all the fights unique and tricky instead of fighting copy-paste easy enemy encounters (Nothing wrong with that in other games, like sandbox, JRPGs,... that have different mechanics, I meant only for this particular game).
A trash mob to me means having a large number of the same or similar enemies. The difficulty rating of those enemies is not relevant. So a large mob of difficult enemies is just as much a trash mob as a large mob of weak enemies, and if anything even more annoying and a chore. I absolutely agree that increasing the number of enemies does not make for a good combat experience. But this doesn't change if you just go from a lot of enemies with 10 hp each to a lot of enemies with 100 hp each.
