the relationship between Diego Simeone and Joao felix has soured since the middle of last season. So Atletico Madrid decided to lend Joao Felix to the Premier League clubs at that time. And initially Man United was a team that wanted to borrow Man United. But the offer was rejected by Atletico Madrid. And then Chelsea also approached Joao Felix and finally managed to borrow J. Felix. And J.Felix's contribution at Chelsea is also quite good. he was just unlucky because Chelsea's condition at that time was really chaotic. even for half a season there he had to adapt to 2 new coaches namely Potter and Lampard. And then the moment of the new Chelsea coach came along. it turns out that J.Felix is also not included in the list of players that the new Chelsea coach wants. So that J. Felix was returned to Atletico Madrid. but it's a shame it seems that Diego Simeone also still doesn't like J.Felix. So the fate of J. Felix is still uncertain. Somehow this very good player is difficult for these coaches (Diego Simeone and Mauricio Pochettino) to accept. In fact, from my point of view, J. Felix is a pretty good player.
I agree with what you said, I also see João Felix as a good player, and Pochentino and Simieone are coaches who, in the teams they are coaches, have had strange choices and because of that they have not been able to win anything big like the Champions League and the local leagues constantly, just see that atlético madrid doesn't play very well, in all seasons atlético madrid is not a candidate to win la liga, so with simeone atlético madrid stopped in time, it doesn't have any great future. That's why joao felix would do very well if he didn't return to play for atlético madrid.
as for chelsea i would say the same thing, you can't expect anything big from chelsea with pochentino in charge, at most perhaps chelsea will be able to stay in 4th place in the premeier league, i didn't see them making big signings but i saw them selling a lot of players, so it's not as if joao felix was going to lose anything by leaving chelsea, now the problem is that he already said that he would like to go to barcelona and that it was always his dream to go to barcelona, but i doubt that atlético madrid would facilitate a selling him to barcelona, so we'll see joao felix sitting on the bench at atletico madrid
Actually, Manchester United was also mentioned as a team interested in borrowing Joao Felix this summer. Because Manchester United is having trouble getting a new striker. And if Joao Felix is at Manchester United then I'm sure a talented player like Joao felix will definitely be appreciated by Erik Ten Heg.
Diego Simeone I think he put too much emotion in the formation of the squad at Atletico Madrid. So that his relationship with Joao Felix also did not improve even after half a season Joao Felix played at Chelsea. It seems that the president of Atletico Madrid still hopes for Joao Felix. but Diego Simeone as the club manager turned out to have other thoughts. I am also quite sure that if Diego Simeone's attitude is still like this then Atletico Madrid will find it difficult to win a title in any competition.
About Chelsea I really don't understand because the new Chelsea coach sells more quality players than mediocre players. And instead he prefers to retain players who are not too good. I don't understand the direction of his thinking.