I think he's actually easy enough to stop. He wants to run straight past people. Teams have figured out that they can foul him before he gets going.
In the last couple of months, he's been kicked, shoved, smashed, clattered, tripped, bashed, whacked, thumped, and more. I'm torn between admiring him for just going for it regardless, and pitying him for being so naive.
A better footballer, a more crafty and clever player, wouldn't be caught in this way, repeatedly getting taken out, usually just getting a free kick by the touchline, 40 yards out. He'd draw 'better' fouls in more dangerous areas, or get his opponent booked or sent off.
Messi certainly wouldn't go blithely charging in to the goalkeeper's path for a ball he can't win, because he knows if he can't win the game if he ends up in hospital.