Easy to say that when the offer and temptation of insane money like that aren't yours to accept.
Of course they earn a fortune already but it's all relative to the situation they're accustomed to. They don't look at it from the same perspective as us. 300k a week the average person is unimaginable but footballers exist in a bubble where it's completely normal to them. and they live a lifestyle, buy houses and other things thar are also unattainable to the average person. So they see a payrise no differently to anyone else and will jump at the the chance to double it.
So it's easy to say we would turn down the offer to double our income in their situation, but in reality most people can't even imagine being completely normalised to being a multi millionaire, earning hundreds of thousands a week as a young adult. We would look at it from an entirely different perspective when conditioned to that lifestyle.