I agree that the variant human is the most effective race for most builds, and that is because it is the most customizable (even allowing a feat at first level). And it is likely that the changes in Tasha's will change that balance.
At the same time, however, of the races that are in the PHB and subsequent volumes, I think there's no doubt that dwarves and elves are both the most powerful and the best supported (have any other races been given exclusive subclasses?). And, with these changes, that gap -- between elves and dwarves on the one hand and all other races except v-human -- increases. Not only can stats now be shifted, but the weapon proficiencies can be swapped for multiple tool proficiencies; an option available to very few other races.
Increasing the spread in ability doesn't make sense. If we were talking about backgrounds, for example, and said that each background provided 2 skill proficiencies and 2 proficiencies in languages and tools, but sometimes they provided 6, it would pretty obviously be imbalanced, and the obvious solution would be to give everyone the 6, if they wanted it.
The only reason not to do that here is because the player or DM wants elves and dwarves to be more powerful than other races. It was suggested above that this might be a mark of longlived races, and if that's your approach, great -- you have an in-world reason for the mechanical imbalance. But it is an imbalance.
If you don't think it's an imbalance, and that tool proficiencies don't mean much, then DMs might as well give up to four extra tool proficiencies to any character (except v-human?) for free. That would also solve the problem.