As a fan of high-level play across the editions, I've never agreed fully with the idea that the game breaks down. I think, however, there's some validity to it, but only if you look at it a certain way. What people are recognizing is that, at a certain level, play changes.I'd like to clarify. When I say that high-level play breaks down, what I'm saying is that the math of combat and game rules no longer function. I am not focused on how the game "changes". In fact, in some editions the game doesn't really change at all.
Further, the ability of characters to whittle away enemy hit points bogs down. 1d8+5 damage at level 2 could slay a monster with 32 hit points (Level 2 Elf Archer, Monster Manual, page 106) in four hits or about five rounds. At level 24, that same dragonborn warlord isn't even close to the same performance against an equal-level artillery threat (Great Flameskull, Monster Manual, page 109). Against the Great Flameskull, the warlord would need a +32 to hit bonus to equal his chance to hit the elf (which is probably 5 or more points higher than the dragonborn actually has). In order to kill the Great Flameskull in the same number of rounds, the hero would need to dish out over 58 hit points with each hit and that's probably double the damage actually done by a level 24 warlord.
Nothing has fundamentally changed but the game got slower and the hero is less able to take down threats than before.
Monte, Legends and Lore reads like you're dismissing other's observations as being in their heads. I may self-define myself as a person who doesn't care for high-level play but many who prefer epic level games also comment that play breaks down. It just doesn't work to lump everyone together and wave away the problems.