lets see. rumble doesn't lose that many lanes mainly because he got a spammable shield. and no resources. also he has decent base stats and hes fairly tanky because of his build as well. you can't trade with him as melee unless he fucks up. and its not often because his Q cooldown is so damn low.
but what makes him pure bullshit is the fact that hes so good in team fights too. hes one of those champions that basically you have no control on whether he does well or bad. if your team is bad to position poorly in choke. you lose. if they flash out of his ult or stay in open spaces. then you win. sort of like miss fortune you don't really have much to do other than pray to the gods that your team knows how to position.
he isn't unbeatable in lane. you can beat him with few champions. renekton works. fiora sort of works riven works. darius can work. hes meh. strong champion but he doesn't have much outside his ult late game. treat him like a mage juggernaut. has 1 thing going for him. just hope your backline isn't stupid enough to not flash early or position badly.
as for melee tops not many beat him. but hes still beatable. hes very susceptible to ganks. because he always pushes so again you have to depend on your team. this case the jungler. to do the logical thing.
he doesn't have as much kill pressure as quinn or pantheon but hes a better team fighter so i guess thats a reasonable trade. Q damage should be toned down early to allow for some fair interaction in lane other than sitting under tower. or at least his tankiness.
tldr: league as a game is designed for high elo who understand what best to do for the whole team not as a single player.