Good pro-ban arguments
Similar reasoning for why Dynamax was banned/restricted in OU and other tiers: it makes almost every good sweeper as scary as Sigilyph/Linoone/Xerneas/etc. during gen 7. Like Z-Moves, just because Dynamax can be used by every Pokémon doesn't mean they benefit from it equally, so the argument "both sides can dynamax" isn't really a good argument. It also creates some toxic interactions where the one with the sweeper is almost always at an advantage (ex: should I Dynamax to stop this +1 Zekrom who would sweep my team if he Dynamaxes, only for him to switch out and lose your Dynamax). Dynamax is unfair because it heavily benefits sweepers, and due to the random nature, not everyone would have a good sweeper that can abuse dyamax well.
Good anti-ban arguments
This is what separates RandBats from regular tiers. Bans from regular tiers would completely stop overcentralization/unhealthy mechanics from staying in the tier. The goal of every ban is to have a "fairer tier". If a new threat become broken as a result of the ban, then it is banned as well. This doesn't apply to random battles. A Dynamax ban wouldn't stop the unfairess. There would always be unfairness as one player can have a weak team, while the other would get top-tier threats, and we can't simply solve this problem with a ban like regular tiers. Yes Hawlucha has a lower chance of instantly sweeping most teams without Dynamax, but the chances of me getting a team that can't check a +2 Unburden Hawlucha is still there.
For regular tiers, they mainly revolve around skill, while random battles revolve around skill and luck. This is why this suspect is one of the most subjective ones. Banning Dyamax would make this tier much less reliant on luck, but it doesn't eliminate it. Winning with op Dynamax sweepers is just as valid as winning with op teams without Dynamax. Pro-ban arguments want to make this tier more competitive, while anti-ban arguments want to make unfair Dynamax wins just as valid as unfair wins from op teams or Pokémon.
Similar reasoning for why Dynamax was banned/restricted in OU and other tiers: it makes almost every good sweeper as scary as Sigilyph/Linoone/Xerneas/etc. during gen 7. Like Z-Moves, just because Dynamax can be used by every Pokémon doesn't mean they benefit from it equally, so the argument "both sides can dynamax" isn't really a good argument. It also creates some toxic interactions where the one with the sweeper is almost always at an advantage (ex: should I Dynamax to stop this +1 Zekrom who would sweep my team if he Dynamaxes, only for him to switch out and lose your Dynamax). Dynamax is unfair because it heavily benefits sweepers, and due to the random nature, not everyone would have a good sweeper that can abuse dyamax well.
Good anti-ban arguments
This is what separates RandBats from regular tiers. Bans from regular tiers would completely stop overcentralization/unhealthy mechanics from staying in the tier. The goal of every ban is to have a "fairer tier". If a new threat become broken as a result of the ban, then it is banned as well. This doesn't apply to random battles. A Dynamax ban wouldn't stop the unfairess. There would always be unfairness as one player can have a weak team, while the other would get top-tier threats, and we can't simply solve this problem with a ban like regular tiers. Yes Hawlucha has a lower chance of instantly sweeping most teams without Dynamax, but the chances of me getting a team that can't check a +2 Unburden Hawlucha is still there.
For regular tiers, they mainly revolve around skill, while random battles revolve around skill and luck. This is why this suspect is one of the most subjective ones. Banning Dyamax would make this tier much less reliant on luck, but it doesn't eliminate it. Winning with op Dynamax sweepers is just as valid as winning with op teams without Dynamax. Pro-ban arguments want to make this tier more competitive, while anti-ban arguments want to make unfair Dynamax wins just as valid as unfair wins from op teams or Pokémon.