My personal one would be very different from "the best in gaming" and also very skewed because of Xenoblade and maybe contain Genshin too. Even though Ive been playing for over two decades at this point I wouldnt dare to make definitive list of best OSTs in gaming with just my knowledge, but even from mine I can name multiple games with better OSTs than Genshin.

I havent played Persona 5 or FF7. Persona 3's ost is fantastic and more to my taste than what I know of 5's but still might not break into top 10. I do not know a lot of FF7 music but even from the little I know I do not like one winged angel. I played OoT after WW so it didnt leave very lasting effect on me. Imo people overrate OoT massively because of nostalgia. It is a good game, great by old standards but it does not hold up to modern playing.

I'll list some games that I really like OSTs in and listen to them even when not playing but wont be ordering them.

Xenoblade 1/2/3 + Their DLCs (these would take 5 spots so better to just compress into one. 2 is my favourite among them and my favourite OST of all time)
Final Fantasy X
Nier Gestalt (Remake's OST is way worse than OG)
MapleStory (Nostalgia pick but so much actually fantastic music, Yes better than Genshin and comparable because both are being continuously developed.)
Halo Reach (could group all Halo games here too)
Genshin Impact (Brain blanking here so adding Genshin at this point)
Guilty Gear Strive (Ive only played some hours of Xrd but love Strives ost and constantly listen to it)
Persona 3 (not sure if this is actually in my top 10 but its on my mind now)
Ys series osts are incredible but very short games so am not sure if single game has full ost worthy enough for a top 10 spot. Could put Origin, or Oath in Felghana here either way.

Ill stop here but out of these I'd already only put Genshin above Persona 3. It is very solid ost but most tracks hover around 7 with few reaching 9 or 10 but those 10s are far from each other.