You can't really judge Licht by Vea and Mayfield because you don't know their demands. You can even see that Mayfield probably describe the state of play a little unfairly
Licht is being judged by former team captains openly pushing back for a variety of reasons. Vea cited lack of communication on any contract. Mayfield cited a low ball contract offer which makes him feel disrespected. Evans rejected a higher offer from the Bucs and wanted to play in a better situation.
If you think it is about "contract" demands you are not reading what these players are saying. Mayfield has said he is willing to listen to reasonable offers and past history shows that given he signed a reasonable 3 year deal. Evans has played on shorter deals in the past but he was not biting this time around. Vea may have still been upset about not having a contract offer but at least the Bucs would be clear with their intent with Vea.
White wanted to get out of dodge and literally took a job with the Commanders where he is basically doing the same role as he had with the Bucs.