It's not quite that bad. But it is certainly closer to that sort of linearity versus something like FFXV.
FFXIII is like the most linear you can possibly make an RPG, it's crazy. The feeling of linearity is the big issue, cuz there's almost nothing else to do(at least not until quite a bit later in the game). Even FFX had some sidequests, backtracking, towns, that could all break up the pacing a bit.
FFXVI also has enough pacing breaks and whatnot to not feel as linear as it is underneath, which is important.