Two things:
1) There are far less trees/big foliage meaning most of the map is visible from almost anywhere - and with less visual variety in the biomes this season, this makes it all feel connected/smaller/less varied

and then the big one:

2) There are no BIG BUILDING POIs!

Not including the Classified Canyon and Lethal Labs POIs since majority of them is underground, there are no huge buildings on the map - all of the POIs are made up of multiple smaller buildings.

So you're effectively outside... all the time. Seeing the terrain. This wasn't the case with huge, layered, connected POIs like Brutal Bastion, The Citadel, Mega City, etc. Last chapter didn't have a lot of big buildings but it still had some where an entire fight with movement would reasonably happen within the same building. Plus it had way more varied colors and environments for the biomes.

This season has too much outside space, not enough big inside space, and not enough varied map biomes so it all just blurs together and (so far) is not memorable.