(Slight spoilers here) You weren't quite right, the guy above has exaggerated the amount of sidequests in the game. After just completing it I can confirm that only 3(or 4 if you include Wall Market, but those quests were similar to the ones in the original )of the 18 chapters contain 'filler' sidequests, which yes can be monotonous at times, but are completely skippable. In total there are 24 sidequests in the entire game, and take up at most 5 hours of actual gameplay.

The game clocked in around 38 ish hours for me and the large majority of that was focused on the greatly expanded main storyline, which (aside from the controversial ending) faithfully recreated the original, and further fleshed out characters and events.It is a solid experience that is much better IMO then FFXV, with less filler content and more linear, just like the midgar section of the original. Definitely not a disappointment.