I don't use Launchpad but I can say, for me, Spotlight sucks! It decides at random times not to complete. I have it set to show apps only. I don't want it to find other things. But quite often I'll press Cmd-Space and type something and it won't find it. For example I just tried "pho" and it did not show Photoshop (which is on my system) but did show stuff completely unrelated to apps and I double checked, I only have apps selected in the Spotlight Search Results section in settings.

This is a uniquely new-macOS issue. Spotlight has never worked well since the big redesign in 10.10. In the snow leopard days it was predictable and seemed to be ordered by frequency of use. (There were occasional issues where the entire launchservices DB got messed up, but this can be fixed with an lsregister reset without reindexing all of the files).

This is a bug. The applications need to be reindexed. Happened to me on my work laptop and personal one