[sseagull]

Folder structure (whether email or filesystem) give context. In the same folder may be related emails from other people or with different subjects. Search works for finding a specific email, and folders help finding related emails once you have the first one.

In addition, folders have better discoverability, whereas I find search to be finicky (looking for exact words when I only remember a synonym)

I have a similar problem with google drive. Oftentimes I will find a file that I was looking for, but I know there are related files in the same folder (maybe a spreadsheet used to generate the other document). But I can't get to the folder from the file (as far as I know). If I don't remember some keywords from the other file, I may be SOL.