He's had a good season as a somewhat motivated supersub. Maybe he thought he'd get his place back. I don't think we can rely on that being the case forever though. He was as shit as anyone when we were struggling and he's shown plenty of times he can stop giving a fuck.
I don't know if we should actively sell him but if it's a case of £50m on Lacazette or £30m on Lacazette and losing Giroud and then actually strengthening other positions (lol) then it may be worth it.
You'd have to wonder what goes through his head wanting to stay at a club that insists on only playing with one striker, may spend 40-50 million on a #9, has very little chance of the title and isn't in the Champion's League when you're effectively 31. Especially when that is the same club that decided Alexis should be the starting #9 for 75% of the previous season when in your head you've probably had 2 good seasons with Alexis on the wing and you up front.
Maybe he's still in the France team because he's still got a very good scoring record despite limited game time, but if he has limited game time and a poor scoring record then I doubt he's a starter at the World Cup and right now that feels like his best shot at a major trophy before he retires.