https://en.wikipedia.org/wiki/Aperture_(software)
I would happily pay for an update that fixed outstanding bugs and ensured compatibility with future versions of macOS. It would be nice to have some new features, too, but it is basically "good enough" as it is and I dread the day I can no longer run it. I'm really not sure what I will do.
The claim that Photos was going to be a meaningful replacement for Aperture was obviously a lie at the time it was released and even nearly five years later it is still not true.
I'd have moved to Lightroom had Adobe not moved to a subscription model.