What about humans? They stay at +1 to all? Or do you only allow human variant ?
If you only give +2 +1 to human standard you nerf them a bit for certain builds.
Btw no player is gimped by a +1 difference in an attribute score. At +2 you can start complaining. Anyhow if everything is balanced out over the races you can set any threshold you want, but do not forget to give standard humans 2x the asi of the other classes, e.g. you reduce it to +1 then standard human should get 2x +1 or 1x +2, If you say I want more and give other races a +2 x 3 times then standard human should have +2 for each attribute.
No standard humans under this variant. If you want to play a human, you'll get a feat and you like it.
As for the gimping: it's not about reality, it's about perception. If you have a +2 but could have had a +3, you might not really be noticeably weaker to anyone else, but you see the difference on your sheet every time you remind yourself what to roll when you pick up the dice. This feels like a big deal. This compounds if you wanted to get feats (beyond the first one for being human), because that would hold you to a +2 net mod up to level 8, which you'll absolutely notice in play.