Chelsea do not learn from mistakes, the quality of Chelsea's players is good, young, talented, but the experience of players is more important than young players nowadays. I also don't expect too much from Chelsea this season to get into the top four at the end of the season.
Chelsea's problems stem from their hierarchy, Chelsea under Todd Boehly play like a disorganized team and the management are making too many bad decisions, Mauricio Pochettino is a great coach, but i think Todd Boehly should have signed Luis Enrique, he was eager to get the job, and i was surprised that the deal fell through at the last moment.
Having said that, it is not all about buying players, you need to get the right players and also manage them very well; Chelsea are buying too many players that they don't need, they are not addressing the actual areas that the team is lacking and even if the season just started, it looks like they won't be in any title race, but a top four race.