I think the best way to do have trash mobs lies in the execution of the open world model. If open world is done correctly, in my opinion, you can find low level quests in most areas throughout the world. This gives a realness to the world instead of a "Done with level 1-5 level area time for the 6-10" which sort of breaks immersion and promotes a more linear exploration. I love to discover an area that seems impossible and then come back later when the party is leveled, or going into a high level area and searching for any quests that I might be able to do. This kind of design not only allows for different leveling experiences but also provides the trash mobs and trash quests. BG3 seems to be doing a good job with this atm but the real test to there open world design comes after we leave this first area and how soon we can leave it.
A lot of modern RPGs have basically dismissed the classic idea of "leveled" areas, and adopted the game mechanic of the level of your encounter is dynamic and chosen to match your level. There i very few "true" open world games, or sandbox games. It is like the fabled unicorn, every wants to believe in it, but rarely does it deliver. Even when they advertise open world, there is still a small amount of linear design to direct where the story takes you. Players can get to easily frustrated when they have to keep running everywhere just to find the next stage of the games story. So they will offer a linear breadcrumb to follow, but offer random encounters outside of that path. Which I think overall is the best decision.
Even if that would mean at least separate combat and social interactions.
Personally, I am so against that. I know I see some modern "game journalists" try to say things like that, and that is not a game, that is a movie. Or maybe more like a Telltale game. A story in a RPG should be discovered through playing the game. I think if a player finds it to difficult on normal, there is no disgrace if you switch it to easy (not saying that is you, just replying to your comment). Personally, I have not found any major battles that are so difficult that cannot be overcome. But that is my personal view, if I did find it difficult, I would switch to easy. For instance, I was dying a couple times when I first played the goblin camp. Then I decided to set up a ranged ambush and pull them out to the bridge (there is even a strategy to wipe out the camp without even having to fight them). When they got close, I would run back and fire a round of arrows and spells. The gnolls if you approach (I don't want to get into too many details) but if you come from a certain approach you can get unexpected help from one of the most powerful gnolls. Or use crowd control like sleep.
