I'd agree with sph about having one workspace per activity. I've never had a rigid workflow with lots of permanent named workspaces, but I have a workspace-naming script that lets me label my numbered workspaces after they've been set up.

Other things that help include a fuzzel-based open window searcher and, to be honest, restrained use of Niri's flagship scrolling feature. Most of my workspaces most of the time are the same size as my screen, with the scroll used very sparingly for usually temporary overflow.

I guess it also helps that I never used the i3 scratchpad so I don't miss it.