I think it's a very natural thing for a young player to consider a bigger salary if he has good playing skills, but if he doesn't have any skills and expects a big salary, it will be very detrimental to the team, and it's also very different from players who have getting old so that they no longer see the amount of salary as the main thing on a team.
Incidents like this have indeed become a trend all along, such as Sadio Mane who recently confirmed that he will leave Liverpool. where Liverpool is a club that has made its name soar in recent seasons but due to several factors Sadio Mane chose to leave Liverpool in this transfer market. Most of the wishes of the players choose to leave because they want to taste new challenges in various competition leagues. Salary issues and internal problems are also a big reference for players to want to move to other clubs.
For me personally I can't say most of the players want to leave, it depends on several factors. For example, related players are on the bench more, then players want to leave to get more playing time and they don't prioritize salary. Furthermore, players who have great potential but still get low pay, but when they still have a contract and or the club board can make a new contract by increasing their salary then the player will be willing to stay and that happened to Mbappe too. But mostly, when a talented young player they just want to move to a team that has a great chance of becoming the strongest team in the Champions League, at least it happened to Haaland who finally landed at Manchester City.