Unfortunately, I don't think that 5e weapons can get particularly flavorful with a limited amount of weapon descriptors and little beyond adjusting damage. We see little appetite for 'to-hit' modifiers for weapons aside from cover. It's not to say you couldn't do it, but the game clearly shies away from more complex weapons.
Armor has even less design space.
That being said, I love Dark Sun for all of its differences. I think it was the first campaign setting designed for 2e. At least it seemed that way for all the advertisements I saw in Dragon. It was clear that TSR was showing D&D and AD&D could be something other than the relatively standard settings we had seen in Greyhawk, Forgotten Realms, Dragonlance, Known World.
If a 5e version of Dark Sun can't capture that feel and instead only looks like 5e D&D with a new coat of paint I don't see why anyone should bother. This still leaves lots of options. You could take and example from the 2e Historical Campaign books that provided rules for various levels of fantasy in your historical setting.