Most of these stars you are talking about are young and they don't have enough experience or some of these younger talents are in the teams they can't be in the Champions League just like Harry Kane who playing for Tottenham for years and he has been a good player but his team can't achieve anything yet.
Victor Osimhen is another example who plays for Napoli and he can't have too much hope for winning the title with his team.
For Osimhen and Napoli it was a great season and they had a very good chance of getting better results in the Champions League. Whether Osimhen can still reach the same heights with Napoli, I'm not sure, but he has a good striker and if he can continue to show such a good game, then he will have a good chance of moving to a top club with which he can do it. So far, it's clear that Osimhen would like to stay at Napoli and win trophies with this team, but it's not as easy as he thinks.
Osimhen is a great player but I'm not sure if Napoli as a team can still perform well next season like the way they did last season but Napoli still have a chance of becoming top teams in serie a and Champions league this season. As far as Osimhen is still in Napoli their will still be better performance in Napoli this season, Osimhen is one of the reasons Napoli was able to win the Italian league and I think similar thing may happen again this season.