I really enjoyed XVI. It is not without its problems but overall is a good addition to the series IMHO. I replayed XV as well after not caring for it on my first playthrough. I ended up really liking it the second time around. The story isn’t the best but the game shines in the personal interactions between the characters while you are wandering around and stuff. A lot of the story is really told indirectly through that and I came to appreciate it. Just my thoughts.
I have a real fondness for XV despite everything (maybe I just love the fishing minigame), but man does the game have flaws.
Not only are there pacing issues in the story, but a huge problem was trying to go too big and spreading the story too thin, which really diminishes the strength of XV itself as a standalone product. The story really needs all the supplementary products (some of which never got made, like the Lunafreya DLC), and even then the official DLCs aren't even seamlessly integrated into the base game! You have to take breaks from the main story to play the DLCs at the appropriate time, and that's not even getting into the tie-in movie and graphic novel and I forget what else. It's a bit of a mess.
Still, I agree with you, there are some lovely personal interactions between the gang, and I did end up really just enjoying travelling around with them (even despite the open world quests themselves being mostly dull as dirt).
XV on its own isn't even my least favorite from the series. The game is a lot of fun. It just has so much lost potential. If they could have fixed the pacing, given actual time with Lunafreya, given some setup or fallout for Prompto, etc the game could have been amazing. So much of the plot beats are great on paper and the game just kinda skims past most of it.
Man, when FFXVI is good it’s so damn good, it’s just a shame the side content felt so low budget in comparison. Really enjoyed my time regardless and curious how it shapes up once the major DLC expansion releases.
I liked a lot of the storylines that came from the side content. The fetch quests never seemed too bad because ultimately it's another excuse to kill more enemies.