Changing the "Caster beats Mundane" paradigm

[Tanarii]

Lastly, rolling up a new 1st level character if you died used to be the "correct" answer. Back then, I could enjoy running a 1st level character in a party of 7th level PCs. These days, I'm told that's crazy talk (actually, is that just a 3e thing? Would it be fun in 4e or 5e?).

In 4e, it's far worse than in 3e. Character need to be very close to the same level vs the difficulty of the challenge being presented. (Edit again: it's actually not that bad, a range of maybe 4-6 levels is okay. But given 4e Tiers are 10 levels each that's relatively smaller.)

In 5e, it's not a problem at all if you stick to the same Tier, which is a level band of 4-6 levels. Level 1 characters can easily adventure with level 3-4s if they're careful. Level 5s with 8-10s is not a problem at all.

Edit: I don't really consider that latter different from AD&D or BECMI. In those you don't take level 1 & 2 PCs out with your name level characters. They join a lower level party until they have some experience. Remember, those games weren't really developed for single party play.