Now if I had to contextualize why I'm underwhelmed, it's:
a) The announcements that it'll be the best Insomniac Games ever, etc... which led me to believe we'd see significant gameplay improvements during the showcase;
b) The new things that you described seem incremental to me and don't fix some of the issues I had with the previous installment.
The stealth in particular left me unimpressed because having a portable zipline with you doesn't change much besides making you able to perch takedown your way through stealth segments even faster than before.
That doesn't mean all these little additions are not good, that doesn't mean they won't improve the game from the previous one, that doesn't mean Spider-Man 2 wouldn't be great even with no major change to the formula (it'd still be good); again, I'm just explaining why I was underwhelmed watching the trailer. That's it.
I wouldn't normally care about new boroughs if you were to zip your way through everything in the same way, but as some of you pointed out, smaller more spaced out buildings might make gliding pull more weight in these areas, which would be great. Especially if it ends up making the player have to switch between gliding and slinging in an interesting way, and not just use gliding to not have to swing at all (I hope not). That's why gliding was the highlight of the trailer for me, and the type of new stuff I expected to see more of.
c) I'm cool with set pieces in general but I prefer gameplay. Since most of the trailer was a set piece that was alright to me, well I ended up not enjoying the trailer like that.
d) Oh and I don't like the Venom suit's look
Don't shoot me