I'm surprised to see you so excited about this. Have you used tiling window managers? What does this and a rofi or similar component not have, or a gnome3 script? Not as convenient, yeah.
The big concern I would have if I were these guys is their magic is their UI, apparently, and they've given it away. If they truly have something good, it's some Electron windows inside a gui kit. Not to understate the work, but the work is ahead of them, too.
I've been griping about the tedium of trying to organize tabs (and to a lesser extent bookmarks) for a long time. I typically have hundreds of tabs open and my sanity maintenance method is to keep their number under 256. They're somewhat organized with tab groups but the overhead of managing them is a huge pain point for me. So the visual categorization and search looks like a huge win. I don't care that much about the other stuff tbh :)
Visual organizational tools are very important to me. Even if I'm in the IDE and thinking in code, when I jump tot eh browser for something I want the experience to visual and low-friction, so I don't have to push brower things onto my mental stack, which will slow me down when I want to switch back to the IDE.
I'm very good at remembering where things are, I can pick up a book I haven't touched in months and remember the page I was on, or the last sentence I read to find my place with a few seconds. On the other hand, large scale sorting and rearranging tasks are miserable drudgery so I have a lot of stacks and my bookshelves are, ah, suboptimal.
I'm not sure if this is helpful to you, but at some point I realized that I was using "open tab" to represent many different things. Once I started naming the uses, I realized that I could shift them to use-related systems. E.g., a "to read" tab gets fed to Instapaper and closed. a "to do" tab ends up on a relevant Kanban board. A "I might want to be able to find this again" tab goes into Pinboard. Tabs that are basically apps I want to keep open get turned into apps.
That, combined with relatively small units of work (most of my kanban cards are in the 0.25-2.0 day range) means that I can just go on tab closing sprees frequently.
I ended up liking this approach because having a zillion open tabs introduces a subtle stress and anxiety that's sort of like when I visit a hoarder.
I like the idea of de-convoluting purpose from the information-pile, and indeed there is some weight associated with the thousand-something tabs I have open across multiple computers because they're all "open loops" in some form or another. When I try to deal with it, I often feel resistance to relying on cloud-based services, since it takes a while to get everything you want into that system, and there's the "what-if" questions about service longevity and if they allow exporting complete backups of the data you put in, etc.
Certainly doing nothing about it doesn't help though. I do at least make sure my browser application data folders are part of my file-level backups.
> I ended up liking this approach because having a zillion open tabs introduces a subtle stress and anxiety that's sort of like when I visit a hoarder.
Sort of like when I'm being a hoarder, for me... :-( Gotta try and learn something like your approach. (I'll do that as soon as I can get around to it, i.e. when I'm done with all the procrastinating that's piling up on my to-do lists.)
Speaking as someone who often communicates before considering whether the people I'm speaking to share my background knowledge... this might be a more effective message if you ask "have you tried ____?"
Sure, I know this sounds like well-actually anyway, but I tried to soften it by not asking "have you not used..."?
On any Ubuntu/debian system this is pretty trivial try using apt install. You've i3 which is an old popular program with a big community. You use it with scripts like dmenu. It's definitely more of a "hacker" setup that your parents probably aren't going to want to use, but if what you are doing is focusing on a few documents, it's hard to beat. It's a lot more complete than floating single windows over your pane of code. The Bonsai implementation is slow in comparison.
There are lots of others like bspwm (even more hardcore), but my favorite anyone can use this tiling window manager is easily pop_os's from System76. When I have to use Windows or Mac and I don't have that functionality it is annoying.
This functionality really should just be built into the OS. The mac equivalent hacks have slowly gotten incorporated into official releases over the years (side by side windows), but they seem to pop up and then die, like Spectacle. If these guys want to do more than just browser documents, what they've got to build is essentially a cross platform tiling window manager. Not easy.
I think the closest you could come to hacking this together is with qtile (py) and you could get pretty close functionality wise.
The big concern I would have if I were these guys is their magic is their UI, apparently, and they've given it away. If they truly have something good, it's some Electron windows inside a gui kit. Not to understate the work, but the work is ahead of them, too.