There are some devices that do this, but as you've already noted, they're crazy expensive. There's cheap(er) ways to accomplish the same thing, though.
Assuming you don't need to do any heavy-duty computing on either screen, you could probably get away with a very cheap laptop for the primary display, and something like a Wacom display tablet for the touchscreen element. I'm not sure how compatible such touchscreen displays are with Chromebooks, but most Chromebooks easily have Linux installed on them, which I'd imagine has much better support. Or pretty much any low-spec Windows laptop would also work just fine.
You could probably get away with a decent setup like this for the $500-600 range. The tablet could rest over the keyboard of the laptop, or if you're clever with drafting and have access to a 3D printer, you could probably easily print yourself a mount of some sort to secure the touch display over the laptop keyboard to avoid pressing keys and give it a more intentional design. I don't know how well using an on-screen keyboard would feel, so something modular like this, where you could easily expose the real keyboard without too much fuss, may be a good route to take.
Just use the calendar on your phone. Set an event for a year from now titled "Go back and see if I was right" with a link to the comment in the description.
Food delivery scammers will often do this and blur out their whole street. That way, when they report to their Uber Eats that they never got their order, the support team can't compare the driver's delivery photo to anything and will usually refund the meal because of it.
This is my thought on it, too. I don't disagree with any of the point OP is making, but I think a larger issue is people misusing ActivityPub platforms and trying to make them into something they're not. It's not meant to be a messenger, it's not meant for privacy. Everything being public and transparent is part of the core design of the Fediverse. The idea of private groups/posts on the Fediverse seems counterintuitive to me.
I remember feeling like such a badass when I got a CD player that could read MP3 files burned to a disc. I'd have an entire band's discography burned to a single disc and felt like some sort of musical library with my binder full of MP3 CDs.
Seems like it would be pretty trivial to make a botnet that just went around blocking users from every new top comment/post. Even better if you just manually do it with that old, organic account you never got around to deleting. That would very easily cause a huge disruption for Reddit.
There are some devices that do this, but as you've already noted, they're crazy expensive. There's cheap(er) ways to accomplish the same thing, though.
Assuming you don't need to do any heavy-duty computing on either screen, you could probably get away with a very cheap laptop for the primary display, and something like a Wacom display tablet for the touchscreen element. I'm not sure how compatible such touchscreen displays are with Chromebooks, but most Chromebooks easily have Linux installed on them, which I'd imagine has much better support. Or pretty much any low-spec Windows laptop would also work just fine.
You could probably get away with a decent setup like this for the $500-600 range. The tablet could rest over the keyboard of the laptop, or if you're clever with drafting and have access to a 3D printer, you could probably easily print yourself a mount of some sort to secure the touch display over the laptop keyboard to avoid pressing keys and give it a more intentional design. I don't know how well using an on-screen keyboard would feel, so something modular like this, where you could easily expose the real keyboard without too much fuss, may be a good route to take.