Sadras
Legend
I think the idea is that the dramatic arc/heroes journey can:
1) Begin at x trope below Conan
2) Evolve into Conan
3) Evolve further into Beowulf
Extrnded further, the premise is:
”Only a Beowulf-esque martial archetype can achieve relative parity with the godlike power and breadth of resources of a D&D Archmage (which is overwhelmingly more powerful than spellcasters in other genre fiction) due to reasons a, b, c (one of which is no action resolution for their suite of godly resources).
My take on it is that 5e deals with everything up to Conan but merely touches on Beowulf (epic boons, supernatural gifts).
The game does stop at level 20 whereas 4e pushed on and explored the Beowulf option. Granted in 4e this was done in relatively equal pace to the caster classes whereas 5e has reverted to arguably the more preferred/popular play style of mundanes.
What WotC could do, is to provide a modular mechanics expansion which may attempt to balance the mundanes with the casters. That is certainly an option and falls within the 5e paradigm.