Changing the "Caster beats Mundane" paradigm

[Cosi]

This is, IMO, a narrow definition of technology. As we develop robotics and AI, do golems stop being magical? Is Magic Missile not magical because firearms exist? Does a Tesla Coil negate Lightning Bolt, or a stun gun demystify Shocking Grasp?

Sure, I'd concede that there's an aesthetic aspect to it as well. But I still fundamentally reject the notion that things being dependable, predictable, or consistent makes them not magical. It doesn't. It just makes them useful. If your definition of magic is "not useful", I would not want to play a magic user in your game.

You are right in the sense that the presence of these things, especially 1 & 2, makes it increasingly worse. But 1 is a problem in its own right that's separate from the guy at the gym, or any mundane-magic-distinction whatsoever. In context of d20, This is most obvious when you compare limited casters (paladin, ranger, adept, bard, healer, warmage etc.) with those which are less so (wizard, cleric, druid, archivist etc.)

Not every imbalance is the fault of Guy at the Gym. Sorcerers are worse than Wizards. Is that Guy at the Gym? Obviously not.

Um. Mistborn fight physically, and enhance it with magic. That's the exact opposite of a pure caster. They're GISH.

Which is a kind of caster. Using magic to enhance something else is still using magic.

But yeah, technically almost everything we experience is some sort of interaction caused by the electromagnetic force, and this is a pretty good example of why specialist casters are better for the game then generalists. If Magneto were to go around poking at the edges of his power to influence things that were not traditionally ferro-magnetic (sp?) because they still use the electromagnetic force he stops being "The Master of Magnetism" and instead is just another telekinetic.

No he isn't. He's still "The Master of Magnetism", because what he is doing is still "magnetism". The problem is that "conceptually limited" is, for the most part, meaningless. Mechanical limits are what matters, but if you have those your concept can be as broad as you happen to want it to be. Requiring casters to be Fire Mages or Death Mages or Nature Mages has its uses, but it is neither necessary nor sufficient to balance them.

I still don't know why you think games need to allow people to advance indefinitely or why they should be balanced around a point long after most games end.

It doesn't have to be "indefinite". It just has to be "after the cap". The reason I'm not naming a point is to sidestep quibbling about whether Conan or Captain America or Hawkeye or Aragorn or The Three Musketeers really represents the pinnacle of martial prowess. Because the specific point isn't relevant. And yes, lots of games end before the imbalance between casters and non-casters becomes crippling. Has it occurred to you that they do that because they want to play a balanced game and if you made that part of the game balanced, they'd play it too?

Insisting on balancing the game around some theoretical 430th level play session seems like a bit of a lost cause as the 1-20 actually can benefit from a bit of tinkering with CMD while the epic level game has way bigger things to worry about.

Mundanes are already bad by 11th level. This is not a problem that is "way outside normal play". This is a problem that occurs halfway through normal play at the absolute latest.

Defeating wizards is easy. Stop giving them magic. Don't let them just walk into any major town and buy whatever spell they want. Give them random treasure and scrolls. I spent 5th and 6th level once with no 3rd level spells due to I couldn't afford the crappy ones they had available and no wizard would let me copy theirs.

No. That sound absolutely miserable. If you don't want people casting spells, don't let them play casters. If you let them play casters, let them cast spells.

For number one, I wholeheartedly disagree. People should be allowed to play whatever archetypes they want.

Then the game cannot be balanced. Period. If I want to play Angel Summoner and you want to play BMX Bandit, the game is not balanced. It's not magically more balanced because people want to play those characters.

there really isn't any reason to do so aside from hurting the egos of people who like to play super powerful characters and don't like the thought of mere muggles being able to compete with them.

That is a very good reason to do so. If your "super strength" does not make you stronger than the guy who has no superpowers, you do not have super strength. If I am going to have powers beyond the mundane, I have to be better than mundanes. By definition. That is what my character concept requires, just as yours requires that you do not have superpowers. Our concepts are not compatible.