I don't understand the aim of this post honestly. A background story and level 1 is what you get when you start a D&D campaign, even if you play an elf who's 200 years old. I don't see the point in arguing about this at all.
There are players who feel cheated if they have to start at Level 1 (actual or the equivalent on other games), in PnP and CRPGs. Some player just want to dive straight in a 'Uber-Mega Level' without having to go through all the tedium of building up to it.
It's a different style of gaming, but one I am glad BG3 is not all about. I enjoy the story of earning those XP and levels, of facing ever-more difficult tasks and stronger enemies. For me, starting at higher levels is as unsatisfying as using a cheat God-Mode to power through the game to the end. I have, after all, invested money for a game. I want playing that to the conclusion to be a long and leisurely experience.
Each to their own, but I'll stick with the slow route.