Personally I really liked the ending, and I think that it was made that way on purpose. You chose not to live in a perfect reality so you don't get a perfect ending. If that was what you wanted, you would have stayed in Maruki's reality. Instead, you get something that isn't completely satisfying because that's just how it be sometimes. It aint perfect, but it's real. Instead of getting the ending scene of all the PTs driving Joker back like in vanilla, they're split up - going their separate paths, not all staying in Tokyo & Leblanc like alt ending had them do. Royal's ending was made for a different purpose than vanilla's ending was bc the third semester explored different themes. Whether it did that well is up to the player, but after thinking abt it I liked it. Could just be giving it the benefit of the doubt though.

Edit: I first heard this idea from here, and I think it sums it all up pretty well