Hi sifus,
Realme XT (8/128) vs Xiaomi Mi 9T (6/64). Both similarly priced. Not much of a gamer, at most play car racing games.

XT pros: RAM, storage, UFS2.1, super Amoled, splash resistance
Cons: never used Oppo or Realme before so reliability and ease of use are unknown to me, notch (not a deal breaker), slower SoC

Mi 9T : notch less, led notification light, branding, SoC, better camera (?)
Cons: RAM and ROM (not expandable), no call recorder, only amoled,