There are supposed to be bits in between, side paths, towns to explore, people to talk to. FFXIII not only has literal straight line areas, but more egregiously puts a load of interesting set pieces one invisible wall away from being explored. "Oh, check out this beautiful crystal area," that you can never explore. "Oh, we finally made it to town. Good thing we don't need to shop outside the save points!" Other games have a thin-veil of exploration, things to make you feel like your experience is unique, interesting, and engaging. FFXIII is literally "walk forwards (not necessarily straight), avoid enemies (since levels are capped), and push the story."
For a more recent comparison, see FFVII:R. It's actually super linear, from movement between towns to areas to explore. There's very few places you can step off the trail. But there's also sidequests, missions, VR fights, and arenas to distract you. You don't feel like you're railroaded through the main quest.
I like the game. I think the characters are interesting, the gameplay is great (once you get out of the 5 hour long tutorial), and exploring pulse is actually exciting.
More of a 50 hour tutorial as Pulse is in chapter 11 and just a big field so not really that exciting imo.
