The compressed maps as such are great as it means you don't have to spend ages running back and forth.
That's why there is fast travel from everywhere on the area.
So your argument isn't quite valid...
The fast traveling option would even encourage having less compressed theme park maps.
I like to compare this game maps to the worst example of the Infinity Engine: Icewind Dale 1. The first real set of maps (crypts) shows how a poorly design map can pad the game exhaustively.
"Fight skeletons, loot...inventory full. Walk back to the shops for 5-10 minutes depending on how deep you are in the dungeon. Walk all the way back and resume fighting. Inventory full, repeat."
They're large maps with loads of things to find in them, but you really spend a tremendous amount of the early game backtracking over and over to start generating gold for decent equipment.
I think BG3 (and 5e in general with its more "level playing field") have set a really good balance. There's stuff everywhere to do and explore, but not so much of it that you're doing endless runs back to the traders, and even if you do decide you need a quick break, the fast travel runes in lore friendly "broken magic weave" let you get back there relatively quickly. Quick trips to camp or through the waypoints mean there's more time for adventuring.
Note: BG1, BG2, and many of the more recent spiritual successors also don't have the problem Icewind Dale 1 does.
