I was getting circa 7,000km out of Ultegra BB.
My current Hope BB has 34,000km on it (including 2x 1000km+ Audax).
The Hope BB cost a bit more, but I think it has paid for itself relative to replacement Ultegra BB over that time.
The only thing I’ve done with the Hope BB is to remove, clean and regrease the face and refit.