De Gea is getting old and maybe that's why Manchester United tried to decrease his salary for the next season since is a famous payer and achieved many goals for this team. It was not good to ask this from De Gea however I think it was not about salary but that's mostly because of Ten Hag, he prefers to work with the goalkeeper he had at Ajax
Initially his salary was going to be cut by 100k per week and De Gea agreed somehow Manchester United wanted to renew his contract again and here De Gea did not agree and decided to move, we don't know if he moved because his salary were lower or he felt disrespected as a legend. actually Manchester United were criticized for what they did to De Gea but their decision is fixed and does not change anything.
After all, De Gea's salary increase at that time was due to Manchester United making efforts to restrain De Gea so hat not leaving to Real Madrid. So, if at this moment De Gea's salary is lowered, then I think that's fine because after all, age will certainly affect whether a player deserves to be paid handsomely or not. After all, if De Gea still wants to be paid handsomely at a no longer young age, then De Gea can choose to play in the Saudi Professional League. Because there are clubs that play in the Saudi Professional League, they are still willing to pay a premium for legendary players who are over 30 years old.
But I think De Gea's reduced salary was not only because of his old age but De Gea's own desire to continue to extend his contract and still stay at Manchester United even though his salary had to be reduced.
De Gea's loyalty to Manchester is not only because of money, but he really loves Manchester United because for several years De Gea has always contributed well there.
Despite the decision by Manchester United officials to expel De Gea, they had no choice but to accept offers from any club, even if they had to part ways with the club he loved.