Lv 1 doesn't necessarily mean "clueless nobody who just started adventuring".
DnD allows you to create a character with an already rich backstory, full of a prior life, and that doesn't have to translate into "high level".
For the purpose of "ludonarrative cohesion", it is easily reconciled: Your character simply decides to employ abilities of increasing power just as the threats increase that require them (and as their "XP", as a representation of that, increases as well).
I'm going to quote you every time some dnd guy whines about it. However, I do think that the reason people complain about it is because the story is just not good enough for them to suspend their disbelief. This means the solution shouldn't be to create a 7 level characters but to improve the lacking elements of the story.
About snowflakes - the issue here is once again with Larian's insistence on origin characters that are also potential companions. This creates so many narrative problems that Larian doesn't seem interested in solving
