You sure seem to have a lot of opinions about macOS/iPadOS multitasking for someone who didn't know about something as foundational as the split view functionality in macOS. Which has been there for half a decade or more.
..really I don't mean to come off as testy as that, I can see you're arguing in good faith here. It's just annoying that people always bitch about the lack of "conventional" multitasking in iPadOS when it seems like they'd actually be happy with an enhanced version of what Apple has already given us. Suppose Apple decided to allow horizontal split views, or splits within splits (like say, a horizontal app on top, and three vertical side by sides below), with the limitations on the number of splits and apps being based on screen size and memory requirements (on both Macs and iPads). Assuming the UI for doing this was simple enough - which would be tough to pull off, admittedly - would this address your workflow needs? It's a serious question. I feel like Stage Manager exists almost to demonstrate just how annoying multiple overlapping windows can be, especially on small screens. It just makes me love split view (+ slide over, PiP, quick notes, replyable pop-op notifications, etc) that much more as a truly superior multitasking system. I just don't think people who for some reason see the Windows 95 multitasking model as the be-all end-all of productivity have really given it a shot.