Before stating this please note I am not commenting on the frequency of these events, just the events themselves.
When a strategy game is build, initially many strategies will be viable because a Nash equalibrium hasn’t yet been reached. This is typically the most fun portion of the game because many strategies can win. Players feel they have the freedom to compete as they choose.
As a game develops however, dominant strategies are replicated and creativity become stagnant. This makes the game far less fun, especially for new players.
The only way to fix this is to create new strategies to alter the meta/dominant strategies. These new strategies are implemented by creating overpowered heroes which force current meta to be abandoned. This changes the game and keeps it fresh.
As a player you have no right to a dominant strategy and games that lack this meta change typically are left only with the top tier of players as new players cannot compete.
Focus should be on making the new meta obtainable for all, and not on the fact they are overpowered. Of course they are overpowered, it’s by design to change the meta.