The only people who want to start on fair footing with minmaxers are other minmaxers.
Edit: also, where did you find the info about 5e being fundamentally designed for starting with 16 in the attribute?
I don't have an official source that would tell you so. It's more of an understanding I've developed over the years of dm-ing 5e and interacting with the math. The whole CR system for rating monsters factors their AC and HitPoints into a defensive score which represents how difficult they are to kill, which factors into their overall challenge rating, which is then used for designing balanced combat encounters. Whenever I deviated from the curve by, for example, allowing players to start with 18+ abilities, they would easily steamroll any by-the-book encounter even after adding an enemy or two. As a similar example, I once had a player with a tiefling fighter with 15 Dex, whom I later allowed to respec as if they'd started with a 17 because it was an atrocious experience for them. A +1 difference is very easy to underestimate, but its impact is far-reaching in a d20 system, especially when it affects frequent rolls which are crucial to your success..
If it sounds like I'm only generalizing based on intuition and personal anectodes, please bear in mind that all BG3 companions as well as
pre-made characters at dndbeyond follow the same pattern and I'm quite sure they do so for a reason.
Not quite true. 2014 5E D&D's baseline playtest characters have a 15 in starting main attribute.
That's interesting. I had no idea since I wasn't around for the release of 5e, but I can't seem to verify this. According to
this page all playtest characters for 2014 5e started with a 16 or 17 in their primary ability, and so did those during the 2013 DnD Next playtests.
