modern Spaces apps? I miss HyperSpaces and the ability to do 2D setups.

it looks pretty good although i'm trying to stick to open source stuff. but who knows,,,

basically read what u/zphou wrote. while terminal emulators, notepads, and other coding tools are very resizable and benefit from complex windowing layouts, a lot of media production software is designed to be used maximised, full-screen on one or more high resolution screens. the increasingly popular window managers that are floating around don't really help much with workflow for people who use those apps a lot. for instance: i often have a heavy app running on one space where I do the most work, that occupies the whole screen. another space has activity monitors, hardware dashboards, and other helper apps that are necessary to do the work on the primary app. a third space has communication. the fourth has references, whether that's a media player, manuals, or a browser showing something i need to reference. then, i have to switch gears to get into a meeting. i'm going to shut down the heavy app and perhaps the dashboards, but i want to preserve they layouts and spaces. so i'll make a fifth space for a video call and probably add an external screen for note-taking and document referencing while on call. this kind of work is a nightmare with the current way Spaces works. as the other comment also mentions, back in the OSX days Spaces could be configured in a 2D array, so you have a 2x2 or 2x3 grid. the former is extremely efficient because you can always travel to every other space in a single swipe, but larger grids are also quite workable depending upon how often you visit them all. there were apps that let you individualise the spaces with titles and separate walls to make them identifiable. it's not easy to recreate that workflow and honestly nothing has been quite like it for my purposes. i've also run windows for many years and while their window tiling and resizing was quite far ahead, they also don't have a solution of this kind.

Window managers solve a different problem. For apps like video editors, DAWs, IDEs, or anything near-fullscreen, splitting one Space into smaller rectangles is not the same as having a spatial map of work areas. A 2x2 grid made it much easier to remember “top left is editing, bottom right is reference,” etc. my exact thoughts. I'm going to give GridLion and AirSpace a better look. I looked through many options but they're all indeed hamstrung by Apple's (mis)handling of Spaces.

you're right, although I've since found GridLion and SpaceAtlas which pretty much do what I'm asking for. but they're both closed-source and paid, while my strong preference is for open-source packages I can manage via Homebrew.