I've thought a lot about this. It is unfair to compare the two. They're entirely different games and only have a shared name to connect them. They're as foreign to each other as Fallout 2 (my favorite game of all time) and Fallout 3 & 4. Only the name and a few basic concepts are there to unite them. Take that thin connection out of the equation and you'll see how vastly different they are. BG 2 was made for a different player in a different time. It was intended for those who wished to suffer the long path, think through the puzzles and traps, and savor the sweet sensation of a hard fought victory. In essence, it was made for role players. BG3 is made for an era where the majority of players demand instant satisfaction, questlines that don't require thought, cheap and extremely trendy "romances", and insanely beautiful graphics. In that respect, it is perfectly fitting that it uses 5th edition rules, as they were dumbed down for the same audience (and for the same reasons). It's a fine game. It is fun to play. The graphics are very good. It is not, however, anything even remotely similar to Baldur's Gate 1 and 2. Enjoy it for what it is. If you still find yourself seeking an experience more in line with BG2, then perhaps try a different game like Pathfinder: Kingmaker.
I enjoy both, but I've been a part of this EA because I am excited to see what this game will eventually become. That being said, I have long since abandoned any hopes that it will ever be a true successor to Baldur's Gate 2.