And much, much more. And seriously... i see the monk win in MOST, but of course not all challenges. Anything outside their classes is pretty much limited free for all anyway, so we can and should only rate in-class abilities. Expert DOES have obscure skills - and more skillpoints, (but seriously... wrestling a monk in his dreams? That is insanely circumstancial) and the Adepts has a few low-level spells. NO way that catapults him on the scale ahead, and if the monks abilities are weakish. (Yeah the freefall ability should provide movements in higher levels - spiderclimb, gliding - and yeah his self-healing should be a tick better... and yeah Abundent Step and Quivering hands should be usable more often, and he should have a DR/Chaotic growing through the levels... but STILL: Evasion, broad saves, immunities, ground mobility, combat feats... it is not THAT bad)
Yeah, in a straight on one on one fight with little to no preparation the monk has a decent chance. But if you start thinking about doing something that contributes to the party. Monk doesn't do much. Adept and expert does.
And it's not to say that the monk can't have a niche, Wild Monk gets a niche as a decent damage dealer and a party scout. But the core monks niche extremely narrow, since all he does really well is survive, and due to his low HD he isn't actually too good at that. Yeah sure, he's probably better than the expert and the adept at surviving, but his other talents are just not that good.
An Adept and an expert can function as low tier casters and scouts. But the monk just doesn't function that well.
Therefore in a Tier 4 & 5 Party, adepts and expert contribute, while experts are probably just worse than the rogue at what they do. They can still add something to a Tier 5 party. The monk, while more powerful all-round, is not adding anything to the party.
If we are accepting the wild monk/martial monk, I totally agree that he can probably outshine the adept & totally outshine the expert. If not, all his got are better defense and perhaps a slightly better damage output. Still nothing compared to the versatility of the expert and the spells of the adept.