I couldn’t disagree more, while it creates card advantage all of the mythron rares are cards that are understated (except strategos and hate) so they are a liability to summon but you have to summon them.
All though I’m having problems with brome myself and think it should be nerfed, when I’m tilted I’m having no problem with it, because there is a lot of strong AoE in this game.
Hate Furnace seems broken on paper but he is surprisingly bad. There is a bug with him where if a spell was casted which procs an effect that buffs attack it would count. If they exploit this bug its morally ok to reset bug them.
Abyssian, Songhai, Vanar and Neutral requires so much set up that their powerfull effects are somewhat underwhelming.
Vet is really high rolly, requiring you to open the right cards.
And to close this off it always is correct to run mythrons as you’re running less cards in your deck.