I understand why people organize things around them, also on their computer. While I am working I also do it. On Gnome I have 1-2 desktops per tasks when working on multiple things. As you say say, they are "the map of the work", nice metaphor. But, jumping in the next morning I get sort of overwhelmed, especially with multiple tasks ongoing.

Over time I have come to the ritual of closing everything in the evening (end of afternoon really), what is still running is on servers in Tmux labeled with the task number, sometimes I leave Readme's open with instructions to myself (vscode or obsidian), but starting clean works better for me (like OP). I sort of slowly load the context in the morning and start to ramp up. That is what it feels like. It works for me. When I boot up, I have 5 empty desktops and zero tabs open in the browser. But it is all filled up relatively quickly again. I do have rituals/rules, like secondary, longer running tasks (ie long running data analysis workflows) are usually on desktop 4. Element/Slack/Signal on desktop 5, outlook/teams (for current client) + other side stuff in browser on desktop 1. Desktop 2 is very dynamic, usually where I spend most time, it overflows onto desktop 3 when I need more space, both are filled with terminals, vscode, browser windows. I have my laptop screen on the side, but for some reason never use it... I just use my Iiyama ultra-wide with quarter tiling (probably would tile more if Gnome would support it, KDE did, loved that, but love the simplicity of Gnome more).

I'm considering making 6 desktops haha. Oh, I really can't work with dynamic desktops, as I "need" some stuff to be on the final desktop, far away yet easy to reach.

Current client has an Excel file for tasks. Really hate that. Tried pushing her to MS Tasks, didn't really work well. But I also need a large space for context and subtasks. For some data analysis tasks I made a small Django system, with a page (model/view) per dataset. That works very well for us, it was very much worth the effort to set that up. The view grabs in data from several locations so it also helps me quickly look things up.