TwoSix
The Year of the TwoSix
You can have a level-based system and a tier system together. 5e has what I would call a real "tier system" (not the Tier 1-4 nomenclature commonly used in 5e discussion). The real tiers are the "1-20" tier, and then 21+ tier.Sure, but a level system gives you that as far as I'm concerned.
Level 20 is what an actual endgame for a tier system should look like. It feels like the end, and going to 21 is a deliberate choice to play a new kind of game, not just a continuance of the old one.

