Why not?
As far as I can tell, it would only take adding 1 optional Mythic Martial class that gets increasingly mythic abilties from level 11+. Set the parameters as -- this class can be no more powerful or versatile than the current Wizard. Don't hamstring the design with limits like no limited use abilties, no narrative control abilties, etc. Some of ehren's suggestions seem really mythic but 4e (the supposed cool ability eliminating edition) actually dabled with some of these abilties as part of Epic Destinies --- there was one where you could walk to any location on any plane in 24hrs, finding otherwise unknown portals and paths in needed. there was one that let you steal intangible things -- souls, memories, etc.
Keep (or improve) the existing mundane / half caster Figher for those that want that asthetic.
Done.
I mean, I'd also be for reigning in casters as the primary solution but all these discussions are sort of assuming that boat has sailed. People seem to equate D&D = super hero Dr. Strange like high level Wizards. And D&D wouldn't be D&D without them. If that's true then give us the martial equivalent as an option. If we are willing to bring Wizards down then this is a different discussion.