LoL can't be played on the Steam Deck. This is common among the top multiplayer games due to anticheat.
It's almost certain no one bought a Steam Deck primarily to play DotA, and it remains to be seen if any has a meaningful impact on the Steam Machine, but I doubt it.
It's almost certain no one bought a Steam Deck primarily to play DotA, and it remains to be seen if any has a meaningful impact on the Steam Machine, but I doubt it.