From now on it is no longer possible to play like all heroes in Overwatch in Competitive Play. Developer Blizzard recently announced this.
Blizzard will ban one Tank, one support and two damage characters for each competition. The developer already announced plans for the “Hero Pool System” in January and at the start of the 21st season of the Overwatch competition, the new system will come into effect. Four characters are not available to play with each match.
These are the first heroes with a temporary ban: Mei, Orisa, Baptiste and Hanzo. The reason for Blizzard’s decision is that the developer wants to see more diversity in the competitions and bring variation to the game.
The Hero Pool System applies to all platforms.