I tried reindexing a few times (each took a few hours) but spotlight search still rarely brought up the file/thing I was after. Examples:

Spotlight search would bring up a wikipedia entry for app store instead of the app store on my laptop: https://imgur.com/QV1w7Kq

Typing 'finder' and hitting enter (e.g. to browse for a file), would open finder settings, rather than finder itself.

I haven't used it in ~1 year, those are a couple of examples I can recall.