So, I don't quite get this:
You make the claim earlier that HW effectively 'removed', say, leves, Additional Actions, Additional Attributes, etc., just because they didn't make further effort to situate those systems.
But let's consider that 'situating' here, as it applies to leves. While leves do awkwardly section away leve mobs so that others can see but cannot interact with them (or even each others' leves), they do not section leve-runners away from the existing world mobs. As such, leve-runners would frequently complain about having to fight non-leve enemies while doing their leves just because their areas overlapped.
The result, from early beta: to leave room for leves, fewer mobs populated the landscape itself and FATE counts were kept fewer, and their affected area kept more limited, as not to as greatly overlap with leve areas.
So, yes, in terms of situating potential actual open-world elements (instead of solo/party-locked play that just happens to be done in the same area), removing leves actually did contribute something.
Was that 'something' ever acted upon? No. Which is why I'm not a fan of leves removal, per se. But, make no mistake: leves were a really shitty bandaid over a more fundamental issue, and which worsened that fundamental issue.
Relative to their zones, they're... the same travel times. Outside of ARR flight, neither one is any 'easier' than the other. You use your mount to bypass mobs... or you use your mount to bypass mobs and maybe take a single inconsequential hit that quickly heals back up.Different forms of appreciation. One is looking at a painting, the other is interacting with it. Most people will always prefer the easy option, it's why we're in this mess to begin with.
If you're counting making more turns as difficulty... that'd likewise be possible if we had what was suggested earlier -- physics-based flight and mount Stamina. The lack of interaction isn't a problem with going fast. It's a problem with "flying" like some sort of NoClip God-Mode spectator, instead of anything akin to actual flight.
Tl;dr:
- Zone size isn't an issue. Detail count, number of points of interest, are the travel times between them are the actual points of concern, and those were unchanged by zone size. (An abandoned or frontier zone being less populated may instead have more to do with it being... abandoned or... a frontier.)
- Similarly, of all the things to miss from ARR that could have instead been expanded upon, leves are not that. They were a bandaid that themselves previously worsened what opportunities zones had available to them for their design. Combined with smaller zones, they are a large factor of why we lost the open-world dungeons and larger, more complex mob camps from 1.x.
- Most importantly, neither the expanding of zone sizes nor the removal of leves --nor anything for which those would be synecdochical-- are what made the world feel like short of opportunities for immersion. That comes down instead to issues that have been present since 1.x and, especially, since ARR -- the clumping of all uses of interest for the world into relatively few spaces and activities.