This has left me in a real fix. I'm an amateur tabletop game designer, and I've put a lot of effort over the past few years into building assets for one of my game designs in Publisher. I can't really afford to pay for 365 and InDesign/Affinity/etc... I've tried Scribus which has a pretty horrible UX.
As far as I can see, none of these has a satisfactory way of converting/importing Publisher files. The export options for Publisher are clearly inadequate - Word is text-only, PDF loses all of the needed editability, and I don't see any other options. When I opened the .pub files in Scribus, it was clear it would be faster to just re-write the whole thing rather than try to correct all the formatting mess.
I'm now stuck with the prospect of having to spend weeks, maybe months, completely re-building all the asset files from scratch.