If I'm not mistake, Bayern Munich and Leipzig will play in the Champions League, next new season, and we are also talking about new star players for next. Indeed, the young players which I mean haven't much experience, but that's not a problem because the Champions League sometimes can make a surprise. It is possible that they can also become superstars in the future, being in the right teams like Bayern Munich and Leipzig is not bad because usually these both teams often get UCL tickets.
Indeed, the Champions League sometimes brings unexpected surprises, but for Bayern Munich and Leipzig becoming superstars or winning the Champions League is something unbelievable.
It will still take a long time for the two clubs to outperform other clubs from the Premier League or Serie A to have an advantage in the Champions League.
But yes, it could happen in no time if luck is really on their side because in the Champions League there are the strongest clubs in every domestic league.
For Bayern Munich, it is still worth it because they is include in the list of Champions League winners, Bayern automatically has the experience and capacity to qualify for the win Champions League. But for Leipzig, I'm not so sure about them. Based on the data I get, Leipzig's highest achievement in the Champions League is only limited to the Semi-finals in the 2019-20 season and the rest were eliminate in the group stage and round of 16. A significant difference is seen if we compare Bayern's statistics in the Champions League.