> Every time I open my RSS feed, there’s nothing there. I can’t doom scroll through it. Because there’s nothing there. So I only open my RSS reader when I want to read something

That's a waste of a manual refresh action - if you only open the reader when you want to read something, there is no point in not auto-refreshing on open so you can... read something.

> I can mark everything as read and get back to a neutral state. And just like that, I’m done with my timeline. Isn’t that amazing?

Not really, you've described a workflow with the same "FOMO" and "chore" downsides: you have to invest time into reviewing the whole batch of downloaded content otherwise if you mark everything as read you fear you've missed something important that you haven't reviewed it. Some clients can even auto-mark links on scroll so you reduce the risk of mislabeling, but these are still not refined enough controls to tacke the issue.

(and yes, of course there are ads in RSS)

I like mark-all-as-read, but I reeeaaallly like not having a read/unread dichotomy in the first place, since it wires my brain to treating everything like a to do list.

I use the excellent vore (vore.website) for rss and I just get a chronological list off my RSS feeds. My brain has a feature called "memory" that stops me accidentally reading any articles twice, and even better, I don't have a feeling of obligation to my rss feed reader.

In gnu evolution (when it hasn't randomly decided to render the entire message window as all black), you can navigate messages with [ and ] to jump to the latest or last unread message, then depending on whether it decides to actually work in marking the message read as soon as you view it, you can press Ctrl + K to force the message to toggle its read status.

In Outlook, because I have so many folders due to sieve rules, I scroll to the bottom of my account where there is an unread emails view that I scroll through and mark the ones read that need to be, then right click the whole folder and hit mark all as read.

Then I just have to wait for 15 minutes as Outlook figures out how to synchronize all that!

K-9 at least on the 6.x version that I remain on so I don't get dragged into Thunderbird Mobile and it's nasty new UI, the only way to set something to appear in the unified inbox is to go folder by agonizing folder and add it, not something I want to spend the time to do, so I end up scrolling through folders and looking at messages manually.

A bugbear: iOS' default mail client having the "Mark as Read" and "Move to Junk" actions on an all-selection right next to each other (with no undo option) is maddening.

Outlook has ctrl-q to mark as read, and ctrl-a to select all. A tiny error on pushing the button to mark a single mail as read sets everything to read, with no undo available.