imo thats not true that there isn't top players anymore . it's just that you are nostalgic for days when top players played in serie a. there are still top players, they just don't play in serie a . salah, halaand, vinicius, kane, mbappe, yamal, lewandowksi, modric, kroos who are top players now would still be top players in the 90s and 00s. you are just selective choosing.
also it's only been 2 years since messi and ronaldo were in europe top leagues. let's not forget about the two best of all time.