Hume and Galka are categorically the best overall.
Galka has the most HP, which in today's climate matters a lot more than total MP. They also have the 2nd highest STR, only 2 behind Elvaan, highest VIT, tied 3 ways for 2nd highest DEX, and like 4th in AGI. Then they have tied MND with Hume or something like that. INT one stage above Elvaans. They play melee the best, and are actually like 3rd best mages despite having lowest MP.
Hume has the 2nd highest INT. 3rd highest STR. Tied in 3rd for DEX. 2nd highest MND. Highest CHR (it's tied 3 ways iirc, but also lol CHR). Tied in 3rd for HP. 2nd on MP. Basically not 1st in anything that matters, but they play any job basically at a 2nd best position statistically, which makes them the best at XI.
Elvaan have the highest STR and highest MND. 2nd Highest HP. 2nd highest VIT. But then... Lowest DEX. Lowest AGI. Lowest INT. CHR barely matters, but they are tied for first in it, along with Hume and Tarus. They make good melees and kind of good RDM/WHM/DNC due to how their heals/enfeebles work off of MND. But they have to get more MLs than other mages for nuking high tier stuff, and their racc/crit rate are a fair bit lower. They only beat Galka by 2 in the STR department, and that will hardly ever make a discernable difference, even at low levels. Elvaan babes are the hawtest women in game though.
Mithras have the highest DEX and AGI, but they're 4th in STR and 4th in VIT (tied with Tarus). 3rd in MND tied with Tarus. 3rd in INT as well, only barely above Galkas. They're also tied with Galkas for lowest CHR. Their HP and MP values are that of Hume, so basically they're a worse version of Hume that's slightly more accurate both in melee and racc.
Tarutaru have the highest INT and MP and that's pretty much it. In today's climate highest MP means very little due to all the Refresh and ease of access to elixirs via Curios. They are lowest in STR, VIT, and MND. They're tied in 2nd in DEX with Hume and Galka, and then 2nd in AGI. Tied in 1st with Elvaan and Hume in CHR. Lowest HP, though I guess it's not as bad now supposedly. All in all, I think they're worse off than Elvaan in having more stats at extreme lows, because their extreme lows effect how much direct physical damage they take, which they can also take less of, in addition to being more susceptible to white magic debuffs than every other race except Mithras.
All in all though, it doesn't actually matter. Like sure, there is a difference, and the difference is something people would clamor over if it were a gear piece, but...
1) It's not a gear piece
2) A lot of times the technically best gear doesn't actually give any better results than the 2nd or even 3rd best thing. Capped damage is capped damage is capped damage, and if the lowest STR race can do capped damage with physical WS then the difference between it and the highest STR race doesn't matter. Same goes for INT and magic damage etc.
3) There's a lot more disparity between Master Level characters of different MLs, with a lot of the highest difficulty fights in the game being beaten by groups with people who aren't all ML50. Because MLs give +1 to all stats per ML, this means that there are winning groups of the hardest content that have greater stat disparity than mere racial ones. So if the bar to victory says it doesn't matter, then it doesn't. At that point it's just e-peen type stuff and technicalities.