Overall it seems like Larian made an improved version of 5e. I almost want a PHB based on these rules. It’s like an Advanced 5e.There’s definitely some things that wouldn’t transfer to the table top as well like handling 4 boons and buffs to every roll.
I really like the camping supply cost to long rests and the weapon special abilities recharged on short rests.
Regarding mechanics, I’m totally fine with 5e. To each their own, I guess, because I see BG3 implementation as totally bogus. :) Which does not prevent me from loving that game greatly, it’s just “inspired by dnd”, to me, mechanics-wise.
Regarding lore, now, certainly I will reuse it! I’m all in the Forgotten Realms, having read countless novels within it, read all 5e adventures (despite never playing them - I take them as current events context to play my own campaigns), and many previous edition adventures, I’m always happy to get new official lore to make my version of the realms richer. :)
And an other aspect on which there will be a before and an after BG3, for me : roleplaying goblins. My goblins are usually “evil dumb”, somewhat not very far from kobolds, if a bit more petty and snarky. I totally love the full blown insufferable assholes BG3 made of them. I will definitely copy that.