Jester David
Hero
Now, I've never played 20th level in 3e or Pathfinder. And my 4e game fell apart at the end of the heroic tier. The highest play I've seen is 17-18 in Pathfinder, which was in a pretty long couple sessions.
But I played in a 5e 20th level story for four or five sessions. And it worked really well. The characters were mortal and the skilled DM (typically the party optimiser) managed to keep us on our toes with constant challenges that could be really deadly. Rounds flew by fairly quickly, and combat wasn't a slog despite the high level characters. But we still felt fairly epic and had a lot of tools at our disposal, but not an overwhelming number. Meanwhile, concentration keeps buffs in check, attunement limits the magic item Christmas tree, and martial characters can more than hold their own. My wife's totem barbarian was unkillable (even compared to the moon druid) and was queen of DPR.
So while the game does not "support" high level play through adventures, high level play works better than in any prior edition and there's enough high level monsters to get decent play. Especially when paired with NPCs using class levels and mobs of low level monsters.
But I played in a 5e 20th level story for four or five sessions. And it worked really well. The characters were mortal and the skilled DM (typically the party optimiser) managed to keep us on our toes with constant challenges that could be really deadly. Rounds flew by fairly quickly, and combat wasn't a slog despite the high level characters. But we still felt fairly epic and had a lot of tools at our disposal, but not an overwhelming number. Meanwhile, concentration keeps buffs in check, attunement limits the magic item Christmas tree, and martial characters can more than hold their own. My wife's totem barbarian was unkillable (even compared to the moon druid) and was queen of DPR.
So while the game does not "support" high level play through adventures, high level play works better than in any prior edition and there's enough high level monsters to get decent play. Especially when paired with NPCs using class levels and mobs of low level monsters.