Taking away new design space and diluting the game overall. Instead of creating limited environments that are totally fresh (save a very small # of reprints historically) with an annually-reserved slot for revisions, everything gets sloshed together.
> There is still a diverse metagame in standard.
There better be, in standard the meta game is basically designed in a lab and prescribed to the player base. Other formats have done worse, we’ll see how many years they can keep modern interesting before it falls to the same power creep issues the old extended format did.
> New formats like commander have created new competitive environments.
Commander is a casual format, it’s not competitive nor meant to be. Arena has no on-ramp to serious competitive MODO play, the interfaces and economies are entirely different.