A desktop publishing application from Microsoft that focuses on page layout and graphic design.
Sorry, but I've just tried converting a Publisher application to Word and it fails hopelessly. I have produced bookmarks for years in Publisher, printing 6 to an A$ sheet. I can set a page size of 4.95cm by 21cm, put text and artwork in and then ask Publisher to print multiple pages per sheet. I don't have to tell it how many to a sheet it, it can work that out and tell me how many will fit.
I tried a similar approach in Word and tripped over a raft of defaults that are geared to printing text on standard page sizes. It struggled to deal with a borderless printing request and failed in the end. In addition although I told it to print 6 copies per page, it refused to do so, printing just one on the left hand side with an arbitrary border at the bottom in spite of apparently being borderless.
As other respondents have indicated, you have a long way to go before providing a viable alternative. I've just looked at Designer, and besides being online only, it looks like something produced for Kindergarten and completely fails to have facilities to replace functions of Publisher. With the headlong, uncoordinated, rush to renewables for electricity, working offline is something we might have to get used to.
Most applications have now hit the point of diminishing returns in terms of adding features. AI so far is more of a hinderance than a help - it keeps on popping up when not required. Perhaps Publisher could just be left as is and still made available. I have noticed that it no longer appears in the 365 apps. I need to replace an "old" computer in order to migrate to Windows 11, but that means I will loose Publisher if I do so. Since it is not being discontinued until 2026, could you please reinstate it in 365 until the discontinued date.