we should instead ask for the cool things to be taken from the casters? You think that's easier?
Nerf them right into the ground. All the way down there Morty.
Incidentally it should be noted you can keep the crazy caster stuff and even make it stack up well alongside otherwise mundane pokey stabby types.
DCC accomplishes this by making such things unreliable and potentially hazardous. Its a weird place mainline DND exists in where so much of magic just always works no matter what when its as powerful as it is.
And LNO is going to be accomplishing this by trading utility for much more spectacular combat magic, in addition to much more indepth Martials.
Its a lot easier comparatively to balance say, my Fire Caller Sorcerer who can, by max level, litter the battlefield with dozens of embers that explode like mini nuclear bombs causing tons of AOE damage when said embers hit everybody in range for damage, and not just enemies, and when throwing said embers out isn't really any more inherently stronger than a Ranger who could slice and dice through entire armies by themselves at the same level, without any risk of collateral damage to your allies.
And this is only made easier when out of combat, most utility magic is just as much a question of a skill check as any approach a martial would take, complete with failures and additional hazards that other skills don't induce.