Theorymon
Long Live Super Mario Maker! 2015-2024
Honestly I'm skeptical of defog in singles. You barely even see Rapid Spin because 3vs3 gets so fast paced, even on stall teams, so I can't imagine Defog making an appearance!
However as far as I know, Defog also removes Reflect and Light Screen. This might make dual screens fairly interesting in Rotations, because in that metagame, dual screens are so deadly that you actually see people running Chandelure specficaly to nail them (in addition to substitute Pokemom)! Defog has a pretty wide distribution under Pokebank, and you do occasionally see random Brick Break Pokemon in rotations, so maybe Defog has some potential there.
However as far as I know, Defog also removes Reflect and Light Screen. This might make dual screens fairly interesting in Rotations, because in that metagame, dual screens are so deadly that you actually see people running Chandelure specficaly to nail them (in addition to substitute Pokemom)! Defog has a pretty wide distribution under Pokebank, and you do occasionally see random Brick Break Pokemon in rotations, so maybe Defog has some potential there.