Meatwad it's to keep him from being an asshole when he's not getting his usual minutes.
Right, he was acting the prima donna at Brighton before we signed him, and will not coast serenely along if he's not looked after.
From Trossard's perspective he's a great talent who spent his career at lesser clubs and is now at risk of being shelved at Arsenal. He's supposed to be moving to secure more minutes, more years and a final substantial payday at some other decent club.
From our perspective Trossard's the left-sided forward Jorginho, he's a fringe player who fills a couple of positions in our depth chart. We're presumably compensating him for the likelihood he'll play 1,500 minutes in 25–26 and be 30+ looking for his last gig when he gets to.
"We're just giving him more money for the sake of it" doesn't stack up. Can we avoid making "Arsenal's leadership is dumber than a Brendan Rodgers motivational envelope" the explanation for everything that happens ... as a treat?