I think the reception of BG3 is well deserved. It's a really fun game. However, I think there are a few things that could easily be changed to make it even better. I'm relying a bit on the popularity of races for the adjustments I would suggest.
First, I think Humans have been changed sufficiently to make up for the loss of +1 x6 to attributes. However, the reason for that is thematically inappropriate. Wizards, Sorcerers, Rogues, and Warlocks are synergistic because you have have Shield Proficiency (and, to a lesser extent, Light Armor Proficiency for Sorcerers and Wizards). From a power perspective, no problem (and I have a feeling the most popular classes are chosen with these advantages in mind, other than Paladin, though I wouldn't be surprised if Elf Paladins were more popular than Human Paladins, even with all the history of paladins mostly being human). From a thematic perspective, humans are now better with Armor and Shields than Gold Dwarves and better with Shields than Shield Dwarves, which makes no sense. Also, where in any lore does it say humans are better with light armor and shields (and polearms) than anyone else? Get rid of all of the human special abilities and just give them a free 1/2 Feat (the abilities you get for any of the feats that grant +1 to an ability). It's pretty good and it is thematically appropriate; I expect 1/2 ASI would be a really popular choice, which should be limited to an attribute that is not improved with the +2/+1. (Incidentally, Skilled should be one of those 1/2 Feats, which grants +1 to an attribute and 3 Proficiencies that must be used to gain Proficiency in the skills governed by the attribute until you have them all; I'd include +1 CON and 3 proficiencies in anything because there are too few decent Feats that give +1 CON. Alternatively or in addition, bring in Skill Expert from Tasha's Cauldron.)
Half-Elves have the same problem with their Militia feat. It was an easy "fix" to replace the +2/+1/+1 attribute bonus, but they are a good option because of the thematically inappropriate Armor and Weapon (and especially Shield) Proficiencies. Changing Half-Elves is, IMHO, one of the hardest because there are so many different ways you could do it and you have to make sure they are "between" human and elf. My humble suggestion would be to give Half-Elves a free Proficiency instead of Militia. (Incidentally, I think Dot Esports was dead wrong in their analysis when stating Half-Elves are equivalent to Elves because they get Human Weapon/Armor Proficiency instead of Elven Weapon Proficiency. It's the Shield, and to a lesser extent the Light Armor, that makes them a slightly better choice than Elf for 3 of the 4 most popular classes; it only doesn't matter for Paladin.)
Elves are good enough, though I'd give the High Elf the option to choose any Cantrip and open up the option to gain a Cantrip from any class (with the governing attribute for the class or the ability to choose the governing attribute if a cantrip is provided by more than one class). (I'd do the same for High Half-Elves.) Wood Elves are good enough already.
Dragonborn, Tieflings, and Drow all fall in the mid-range for popularity. I'd leave them as they are.
Half-Orcs are not terribly popular but they have the powers that allow them to fill their niche. You can't do much better than a Half-Orc Barbarian, Fighter, or Paladin. So I'd leave Half-Orc alone, too.
The races that really need some love are the bottom 4. The interesting thing about all the least popular races is that they were the only ones who actually lost abilities in the transition from 5e to BG3. Presumably, their lost abilities were there for balance, right?
Give Githyanki Psionic Resistance like they had in 5e.
Give Halflings Proficiency in Stealth. They lost Halfling Nimbleness in the transition from 5e to BG3, so just give them a thematically-appropriate proficiency to make up for it.
Give Rock Gnomes Expertise in Sleight of Hand. They lost Tinker in the transition from 5e to BG3, which was a pretty big benefit, so give them a thematically appropriate proficiency to make up for it.
Give Deep Gnomes Expertise in Stealth. They should be the most stealthy race anyway, even though they didn't lose anything in the translation from 5e to BG3. (I think they should get Expertise because the "niche" of a gnome could be Expertise in something, though I consider this to be the least merited change of all those I suggest.)
Give Forest Gnomes Expertise in Animal Handling. It just makes sense and is far from OP.
Give Dwarves Proficiency with Light Armor. They lost Stonecunning and a Tool Proficiency in the transition from 5e to BG3, so they should get some thematically-appropriate ability to make up for it. Give Shield Dwarves either Medium Armor + Shield Proficiency, Heavy Armor Proficiency, or Heavy Armor Master, depending upon whether they are already proficient with Light (the racial ability I propose), Medium, or Heavy Armor, but without the +1 to an ability. Their niche becomes armor, which is appropriate.
And (tangent) please allow Background Skills that are duplicated by a racial Proficiency to grant an alternative Proficiency. Half-Orc Soldier makes sense, but you lose a Proficiency if you take it, for example.
I have no doubt that the hardest change to roll back would be the change to Humans and Half-Elves, but if you made the changes to the 4 most unpopular races (just giving them a little more to make up for the loss of abilities in the transition from 5e to BG3), then at least Humans and Half-Elves would only be comparable to Dwarves in tankiness and you could leave them as they are.