I live in Manhattan. This is a rip off. The Uber Pool rides can take up to an hour sometimes, they drop off and pick up up to five people on your way. Uber if you are reading this, everyone in NYC realizes what a waste of time Uber Pool is.
How does Uber Pool even work during rush hour? Do you spend all day trapped in Times Square waiting to pick up the second person? Or does Uber try and route around gridlock? Does it just skip the other person if the car gets stuck? Or maybe I'm paranoid because of a bad experience trying to get to a job interview via cab my first time in NYC.
I haven't used it during rush hour myself, but I know some people who have. The short answer is: it doesn't work during rush hour.
All of the issues you've highlighted are issues, but even without some exceptional traffic just picking up and dropping off multiple people makes the whole thing interminably slow.
Not to mention that Manhattan below 125th St is subway central - I can see the value for people in Brooklyn and Queens who live in subway deserts, but Manhattan? Even regular non-pool Uber is already slower than taking the train during rush hour.
I can appreciate that uberpool is a great thing for people in other cities, but the product market fit for Manhattan is exceptionally poor. I wonder why Uber is bothering with this market when there are many others (see: SF) where this "unlimited pass" would be actually useful.