> It doesn't help that gmail, which is the only serious direct competition to outlook, straight up doesn't do "folders" and instead goes with markers.

While true, unless I'm mistaken, markers (I assume you're referring to tags) can be nested to provide a pseudo-folder hierarchy, and with proper filters you can remove the "inbox" tag and have the mail only show up under the specific tag.

TBH I don't fully mind it, it lets you classify an email in multiple ways (eg "See Later" as well as "Work related").

Tags are great but I still want my folders. Also doesn't help that the way google describes some things is unnecessarily complex or confusing. For example, removing an email from the inbox requires archiving it. In most other applications (WhatsApp, Signal, Outlook, etc) archiving usually results in the email being placed in a specific archive folder that isn't readily accessible through the UI. At least not to the same level that normal emails are.