I disagree about tags being best. Best is both. Having an outline format, available in Joplin by nested notebooks and tags is best. There are some things that are nicely handled by an outline type setup and sorting within the final notebook/ section. It is often easier to look at an nicely organized outline and find a sub-section within it without needing to remember the key word used for those things and only those things. For example, finding confirmation from a vendor from earlier this year, is easier with a folder for confirmations, and a subfolder for vendors. - Or for a client, with a folder for clients and subfolder for their purchases. I’d hate to have everything in my documents folder all mixed up and without folders, requiring me to remember hundreds of tags.
I have not noticed any slowdown or delay with tag searches. For me they are immediate. Are we talking about the same thing? Ctrl-G followed by # and starting to type a tag? A list immediately appears for me with all the tags containing that character string.
Admittedly, searching could be strengthened. I haven’t found a way to do multiple tags at all or to search within a note. Earlier today I copied a long web clipped article to another editor to search within that article for a term. - Possibly I’m just missing things.