>>44823249>haina desert, sandy cave, ten carat hill, and mele mele sea just to name a fewName more than them, that's the problem.
It's not just that there's an absence of them totally, but the amount that can be accessed during the campaign is so minimal that combined with how slow SM are in the overworld, going back to them is more of a slog than anything.
Compare that to other games where there were plenty of winding and branching areas that could be accessed either the first time around or just by backtracking a town or two after getting a new HM. SM treats them like exceptions and not the norm.
It doesn't help that SM/SWSH are very linear as is, either. Throughout the campaign, you're constantly following one checkmark to the next, and the game just as constantly punishes you for trying to take your time exploring either by blocking off caves or sections of towns (like Diglett's Cave, the resort, a whole half of Melemele Island). It just gets really tiring.
I will give you credit, though. SM at least had a postgame route that was about as expansive as the wild area wherein SWSH doesn't add anything of the sort after the campaign, making the whole postgame episode a slog as you fly from gym to gym defeating bosses and nothing more. I would have much preferred some upper-class area of Galar where it could be reasonably assumed the twins were actually celebrities rather than hamfistingly just saying that everything knows who they are despite being mentioned nowhere during the campaign.