imagine how beneficial that would be?
You would have fewer unique synergies which would make item- and champion balance easier and patching would require less work with fewer champs to take into consideration. It would remove unnecessary clutter from the client and you would ultimately save money by not having to continuously support dead losses.
sure a handful of one-tricks may be pissed off, but that loss would be minuscule anyway and optimizing your champion roaster this way will offset that loss easily as more resources are now freed up for projects that are actually profitable.
"But wouldn´t people be angry?" Sure at first, but this is where the second step comes into play. Instead of suggesting that a champ will be supported indefinitely you introduce formats, so that players can more easily accept the fact that whatever they are investing in will be replaced in the future. Having formats also opens up a lot of design space for champions and dramatic meta shifts since overdesigned new champs no longer have to compete with outdated ones in a much smaller champion pool and instead they stand in competition with other mostly equally overdesigned champs of the format.
Ofc you can still introduce staple champs that can be brought into the next format to ensure that you can still make money off of your most popular champs of past formats.
Riot just learn from TCGs and don´t hold on to the undesired and ultimately limit your potential to give the masses what they desperately crave.
More ninja, samurai and cute girly skins.