The park has nine rides and three large shows. On top of that, smaller attractions/shows in TWD, Ollivanders, Tri-Wizard and Frog Choir. With SLoP, JW and Nintendo, USH will have just as much as any other park out there. That's not counting, whatever else will come between now and the Olympics. It always boggles my mind, when people continue to say Hollywood is still a ways off. They're not that far off. What this park severely lacks is a hotel. They should've had one when Potter opened, but they choose not to for whatever reason (and no, it has nothing to do with a lack of land). CityWalk is turning into a destination once again and within the next year and a half will be doing better than ever.
Does USH need to add and fix a few things before considering a second gate...yes. But let's not act like Hollywood is all that far off. Attendance is on the rise and with the Olympics coming in 2028 which is not all that far off, Hollywood is going to grow more than anyone could've ever imagined.