look man if you lose baron and multiple inhibitors and presumably can't win a 5v5 away from your nexus turrets anyways YOU LOSE THE GAME. You lost all the objectives, you can't fight them, you deserve to lose and this is the mechanic which makes you lose.
Super minions and baron END THE GAME. No it's not fun to watch them kill your base. Deal with it?? It's not a ton of fun to lose in any game but that is the reality of multiplayer games. Something has to make the game end and half the time that thing is making you lose instead of them
Picture a version of league where super minions plus baron COULDN'T end the game. The enemy would take baron and inhibs, yet you would still live because supers and baron were weaker. Way more games would see teams horribly behind get to full build, which means team fights on even terms because the team who was ahead couldnt end the game with their advantage. That is a BAD thing because it means advantages, objectives and risks are meaningless and more games just come down to one team fight with 70 seconds death timers regardless of how well you played earlier