Great question. If we're talking entirely bad segments, it's hard to beat Alola's second island, where the mandatory stuff is drawn out for no benefit, the optional stuff is so minor it's not enjoyable, and there's the extremely punitive Stountland roadblock that rewards you with the worst fucking itemfinder in the entire series when it's unblocked. It only gets remotely good when the island is almost over. If it's just a single route that's a lot harder. Like, Kalos Route 1 is literally just a waste of time, but so are a ton of routes in Sinnoh and a few more in Kalos and they're way worse about it. If you're talking bad encounter design the trainers in the midgame of Kanto are samey and low level but they're optional, and for wild Pokemon DP Sinnoh Route 215 is a combo of no real new Pokemon (unless you really don't want to catch and evolve Abra) and map design that is both unremarkable but windy enough to be time-wasting which takes up enough mandatory space that the optional parts of the map are extremely unremarkable.
>>56285833Not even the worst mandatory route in any game it appears in (it's probably Unova's Route 5 which still has more shit going on than
>>56285859 somehow)