Yes, once again Larian should deviate less from D&D 5th edition rules. I'm not saying it has to be 100% tabletop rules, but just don't change things without any reason. Also not saying never change any monster's stats or abilities. It's simpy hugely out of place for low challenge rating enemies to have so many attacks.
The problem with melee characters in BG3 is, once again, a result of deviating from 5th edition rules.
- Cantrips creating surfaces, making them hazardous to your own frontline (plus simply overpowered in general).
- Surfaces in general, as every damn enemy has some kind of arrowhead and/or bomb (I'm okay with surfaces if they were a bit more special and rare).
- Jump/disengage as a bonus action invalidates a big part of what makes rogues shine (increased mobility and options in combat).
- There are two optional flanking rules and BOTH of them are implemented in Baldur's Gate 3 (advantage from attacking from behind, advantage from another friendly character engaged with target).
Additionally, there's free camping almost anywhere, even inside the goblin fortress. I'm pretty sure that camping / replenishing spells will be more limited at some point, but right now that's one more reason why spellcasters just dominate.
Agreed on most counts.
To respond to the OP, yes, D&D5e monsters and NPC follow different rules from player characters. Player characters have less HP and do more damage; they have less access to multiple attacks per round; their class limits what kinds of abilities they can access.
Monsters are built using different tools because their function in the game is completely different - their average lifespan is 2-4 rounds; their purpose is limited to being a narrative prop, a challenge, or a resource sink; they are defined by one or two special features or attacks, not by a slew of class-dependent abilities; they rarely have spell slots or consumables to keep track of (they'll be dead before they get to use them anyway); they are often outnumbered by the players (running a lot of monsters is hard on DMs, so it's preferable to have fewer monsters than adventurers. The published modules almost never put you up against a monster horde) and thus have more ready access to Multiattack, Legendary Actions and Lair Actions (i.e., things that break the action economy in their favor). Because they're often outnumbered, it's fine for monsters to have a broad suite of abilities - healing, buffing, movement, control, blasting, all in one package - they don't have to worry about niche-protection like PC classes do.
A monster's 5e statblock isn't its "character sheet", and it doesn't simulate that monster's realistic capabilities. Rather it's a player-facing "challenge sheet" that presents the players with a level- and group-size-appropriate obstacle for them to overcome.
The problem in BG3 is that Larian isn't sticking to the spirit of the above design philosophy. There's no thought given to the number of enemies one goes up against, their action economy advantage, or adapting monster statblocks for the environments they design. Every encounter is "Deadly" by D&D5e's CR calculations, which means the player has to cheese them by using DOS-style environmental interactions. Which throws the system they licensed out the window in favor of barrel go boom.
