The balance of D&D does assume magic items. I'm not saying we should remove those. I'm saying doubling down on that is creating more problems that will have to be solved eventually. Better to pull from Weapons of Legacy, or Unearthed Arcana's proto-Weapons of Legacy subsystem, because that's closer to the source material.
Casters have all day flight -- overland flight is the obvious solution, phantom steed at higher levels, or even fly lasts long enough for a full day's dungeon crawling.
I think the topic of this thread is that giving martials anti-magic is the best solution and we should all support it.