Can’t really argue with his decision here. He’s gone to a famous club, with a huge stadium and CL football. Of course, they aren’t actually ever winning it and everything else beyond home games and a few big clubs will just be a non event. But maybe that’s what some players want?
The release clause is mental, it pretty much means he’s never leaving all the time he has a contract. Unless he’s the next global star, nobody is paying that. Especially if we’ve seen the peak of what clubs are willing to spend.
Release clauses are set way above market value as standard. If someone offers an acceptable fee next summer, Benfica will sell.