Eldritch_Lord
Adventurer
It all depends on player skill and maturity.
I've run games for parties of beginners where the traditional blasty/healy/fighty/sneaky roles are used, and everyone is roughly on an even keel. I've seen mid-optimization parties consisting of mostly casters and mid-optimization parties consisting of mostly noncasters, and as long as everyone knew what they were doing and had appropriate role divisions everything worked out fine. I'm currently playing in a quite high-op campaign where I am the sole martial character who handles most of the combat stuff, hasn't been hit or failed a save in over 7 levels, can kill literally dozens of mooks each round, and can fly faster than the party casters can dimension door; the party casters are a diviner/abjurer arcanist who scouts out our enemies weeks in advance and wards our cities to hell and back, a druidish caster who builds entire fortresses and fleets out of thin air in days, and a necromancer who has undead hordes to crew those fortresses and fleets.
Generally speaking, "casters" outperform "noncasters" at levels above 6th, that much is not in doubt. Individual casters may or may not outperform individual noncasters. If skilled players play their characters to their full potential, then by high levels...sorry Ahnehnois, but noncasters are easily shut down without extensive caster and/or item support if enemy casters know what they're doing, and a caster's most useful contributions are divinations and fortifications out of combat and buffs and control in combat, but because casting rewards versatility and preparedness more than overspecialization, noncasters will generally be far better in their niche than comparable casters unless the casters are focusing in the same areas.
That essentially means that high-level combat turns into casters > noncasters > monsters > casters, depending on the specific builds and monsters involved. It also, incidentally, means that much of the toes-stepping that can happen easily at lower levels fades away, as mundane skills--sufficiently boosted, of course--start to overtake magical utility again now that defenses against magic are common (Hide > invisibility, Escape Artist > walls of force, etc.) and most melee and the majority of ranged combat is best left to combat centric classes because, while CoDzilla and the Mailman are scarily effective (just ask Dandu!
), higher-level play tends to shift away from individual combat tactics towards strategy and logistics and a caster's not-directly-offensive contributions are more valuable.
All of this is in my experience, of course. If players or the DM hold back, or if extensive nerfing/houseruling happens, or if groups decide to stick with lower-level playstyles, or similar, the above doesn't necessarily hold.
I've run games for parties of beginners where the traditional blasty/healy/fighty/sneaky roles are used, and everyone is roughly on an even keel. I've seen mid-optimization parties consisting of mostly casters and mid-optimization parties consisting of mostly noncasters, and as long as everyone knew what they were doing and had appropriate role divisions everything worked out fine. I'm currently playing in a quite high-op campaign where I am the sole martial character who handles most of the combat stuff, hasn't been hit or failed a save in over 7 levels, can kill literally dozens of mooks each round, and can fly faster than the party casters can dimension door; the party casters are a diviner/abjurer arcanist who scouts out our enemies weeks in advance and wards our cities to hell and back, a druidish caster who builds entire fortresses and fleets out of thin air in days, and a necromancer who has undead hordes to crew those fortresses and fleets.
Generally speaking, "casters" outperform "noncasters" at levels above 6th, that much is not in doubt. Individual casters may or may not outperform individual noncasters. If skilled players play their characters to their full potential, then by high levels...sorry Ahnehnois, but noncasters are easily shut down without extensive caster and/or item support if enemy casters know what they're doing, and a caster's most useful contributions are divinations and fortifications out of combat and buffs and control in combat, but because casting rewards versatility and preparedness more than overspecialization, noncasters will generally be far better in their niche than comparable casters unless the casters are focusing in the same areas.
That essentially means that high-level combat turns into casters > noncasters > monsters > casters, depending on the specific builds and monsters involved. It also, incidentally, means that much of the toes-stepping that can happen easily at lower levels fades away, as mundane skills--sufficiently boosted, of course--start to overtake magical utility again now that defenses against magic are common (Hide > invisibility, Escape Artist > walls of force, etc.) and most melee and the majority of ranged combat is best left to combat centric classes because, while CoDzilla and the Mailman are scarily effective (just ask Dandu!

All of this is in my experience, of course. If players or the DM hold back, or if extensive nerfing/houseruling happens, or if groups decide to stick with lower-level playstyles, or similar, the above doesn't necessarily hold.