Spotlight search on macOS is in general kinda…spotty. Now that we have super fast SSDs it should be instantaneous very reliable. How hard can this be? BeOS seem to have figured it out 30 years ago. Apple missed a chance to fix this once and for all when APFS was developed, but they are fat and happy, no fire in their guts. Craig Ferengi must go.
On KDE systems, we have baloo which forms a filesystem index for universal (spotlight-like) search. It's very, very fast and the ranking algorithm for krunner is quite good. I think commercial software should have no issue matching this.
