From watching his 21/22 assists + goals the thing that stood out is just how poor the defending was. Most of the goals were him cutting inside and getting a free hit at goal.
Also one thing that stood out from watching his highlight videos is how he rarely took a player on to the outside, preferring to cut inside, and just how unexplosive his dribbling is compared to someone like Mane or Dembele. I'm not sure that'll translate very well to the PL in a similar way it didn't for Sancho.
Also a google shows me his CL opponents this year were Sporting, Besiktas, Dortmund and Benfica. Last year it was Pool, Atlanta and Midgetland and they got knocked out. So yeah for me anyway a lot of question marks. Especially at a big price point.