I don't think it's realistic that any player could clock an average of 4500 minutes a season for 10 years in a row and cover a lot more ground than Messi, he's gone over 5k minutes a couple seasons, maybe even bordered the 6k including NT games, and traveling to South America on top of that, he'd have to be a physical freak in stamina and durability to stretch the rubber, and he was already prone to injures 12 years ago.
This is one of those topics that have been talked about for hours, you can choose having Messi available for 90', 60 games a year, on reduced ground covered, and yet he's able to make the difference be it in the 10 first minutes or in the 93'. You can't really afford to bench him and lose 45' of potentially closing the game with him in the pitch, we also know that he plays better the more "flow" he finds playing games, to a certain extent, obviously fatigue sometimes catches him in the worst moment.
But still, any Barcelona fan that has watched him play for 10 years probably doesn't have a problem with how much he runs, I'd say it's "weird" that the ones attacking him are people that are biased against him.