The game is very much like chess. There are pieces on a board with movement and abilities. You can use your pieces to defeat the other pieces, or you can be defeated in turn.
The problem isn't the analogy of chess to bg3. The problem is the AI in bg3. If the AI in bg3 could learn and adapt to the players tactics then it would become one of the greatest tactical games in the modern era.
Unfortunately, the AI is static.
Let me add to this a bit.
In chess, the AI is designed to win, to beat you. That's the goal.
In BG3, the AI isn't designed to beat you. It's designed for you to win. The only question is "how hard is it supposed to be for you to win?"
When I ask for a harder mode in the game, what I want is a game where the rules are the same for both sides and the AI is designed to beat you, to win. That way I'm going up against a real challenge.
You probably won't even survive the nautiloid if they do that, because if Zhalk would turn against you instead of the mindflayer, to make sure none of these pesky thralls get to the helm, you wouldn't stand a chance.
Maybe the problem to get good difficulty levels is that the game pushes too strong adversaries against lvl 1 characters from the beginning. Then they need to do all sorts of arrangements to enable those characters to survive.
That is what happened to me in a certain way in my current Honour play. Zhalk killed the mindflayer very fast due to crits, then downed my main and Lae'zel, and Shadowheart barely reached the control panel. I was a bit worried wether it was "game over" that early because of the death of my main, as the others are not true companions of a party in the intro, but luckily she woke up on the beach.
I'm fine with Honour mode, it should not be the litmus test for the true hero/heroine but a difficult but manageable mode with a chance to fail permanently, a bit like in life. More difficulties should be added in Custom mode.
I also don't understand why self restriction is such a problematic feature for some people. I did not use any scroll or potion (other than healing) in my first real playthrough (after EA), did shove only one time, did not look for magical items except what I found by chance (I missed a lot ...), used stealth in combat only for my Rogue, avoided Illithid powers and, above all, never started a fight from the meta instead from the flow of the game. I do the same in Honour mode, to a certain degree at least. In my current Honour mode I was nearly wiped in the Gith fight because I did the dialogue and the initiative went badly, and I was so furious about the 600 gold and the stress that I started the revenge fight from stealth (because they now were hostile) with a fireball scroll I found, shame on me. Why cannot people use self-restricting house rules to make Honour mode more difficult?
What I would really appreciate would be a true 5e DnD mode without the op stuff the game offers to the player (and that's although I never played DnD tabletop).