Earlier quoted context omitted.
Just regular fuzzy finding is the most common. For example, to attach a file instead of faffing around clicking in the open dialog, I type into fluent search(a frontend to everything) and it enters it in the current context i.e the open dialog. It has a few other qualifiers, like big: huge: etc to search large files. Same way with time etc. Rarely when you need it you prefix with regex: and you get everything you nee…
Wait, I didn't know Everything can full search text ? is it like search preview in macOS ?
For the latter, explorer top right search bar can do it surprisingly. As for a tool with an index, recoll comes to mind.