Baldur's Gate 3

That sounds really slow. Maybe just try to. Turn a a blind spot to things and let yourself drift a certain direction not caring about what you might miss will help you, since it accelerates the narrative.

Don't be afraid to change classes or subclasses. The game gave you the option for exactly that reason. If your current character kit bores you, try something else

and opening every crate etc?

Unless you're really hurting for camping supplies, this definitely wasting your time. In my playthroughs I've ended up with soooooooooooooooooo much excess camping supplies by the end of the game.

It's not a bad idea early game to pick up the supplies, but Act I is just chock full of camping supplies. Act II has far fewer because of the Shadow Curse. Nobody is living there and all the food is rotten.

a poisonous bog of some sort

I do not remember a poisonous bog, I just remember the Shadow Curse, which sort of acts like poison and slowly kills you if you don't have a type of protective spell.

Don't skip narrative. But try to recognise what parts of the gameplay are slowing you down and consider stopping them.

I think simply not picking up every little thing usually speeds up the game (and similar games) tremendously. My personal rule of thumb is that it's only worth it to pick something up when it's weight to worth ratio is 0.1 to 1. So a thing that weighs 1 has to be at least 10 gold worth. And by the third act even that was too much.

And for inventory management you should either get yourself some mods that give you automated sorting bags or just don't do it and rely on the search function.

follow the narratives but maybe skip looting every crate, there really isn't much to be gained from hoarding and selling forks

don't be afraid to advance the main quest, it opens up a lot of options and shortcuts - and you'll (probably) know when a long mission with no way back is going to start

and most importantly - don't be afraid to miss things, BG3 is huuuuge, i feel confident assuming you already missed plenty of things, and it's not a bad thing! it allows you to explore the game in a unique way on each playthrough :)

I think the best advice I can give you is to have a friend join you and play multiplayer. That'll make it a social story experience and you'll really find value in it. I think it's a huge multiplier on the game