DPS characters are literally made to beat tank characters in every game.
Tank characters are made to beat burst.
Burst characters are made to be DPS.
I know this is revolutionary. But if you make Tank characters beat DPS in addition to burst characters. The only useful characters will be tank characters.
Let's say we make tanks unkillable by a dps class like ADCs. Who the Fuck is going to kill them? Huh???? Your Leona? Your Rek Sai????? Maybe Katharina or Talon??????? O wait none if those champions can kill a full tank Moakai, Nautilus, Poppy, or Mundo.
Congrats you just created game mode that has 9 fucking tanks and Cassiopeia if for some reason she's not banned.
Team fights are now 15 minutes long and most people will just base race since fighting is futile.