Yes, but it'll get _much_ closer to 0 than e4 or d4, which are already close enough to 0 to produce good games won by black. I wouldn't call it needlessly unfair

It also means White still gets the edge of being able to prepare for the first move vs their opponent, ie they may've studied 1.Nc3 lines much deeper in preparation, whereas currently White gets the edge of choosing the first move & it's advantage

ie White gets to decide whether they prefer their e4 prep or d4 prep against their opponent's prep as Black, so if White doesn't want to play against their opponent's Sicilian they play d4. This is a theoretically moot but real advantage. See Fischer's performance with c4: https://www.chessgames.com/perl/explorer?pid=19233&side=whit...

See also how well 1.g3 or 1.b3 have performed while Stockfish gives both a solid 0 eval

In short, while I started with Yes, I mean No. Because b3/g3 are equal enough that White gets an edge by deciding whether the game will be a g3 or a b3 game