The suggestion to continue using Page Plus on the face of it sounds ok. The latest version X9 will probably work quite well for some considerable time until Microsoft decides to move on from Windows 10. As Page Plus is no longer supported the time will probably come when it will no longer work.
I use statistical sports analysis software with over 20 years of data. It was designed for XP continued to work until Windows 7, but doesn't work at all on Windows 10.
My solution is to buy up old laptops with older versions of Windows that are now, you guessed it. no longer supported by Microsoft.
So my advice, bite the bullet and go with the new software. Page Plus has served us well for years , I'm sure Affinity Publisher will be even better.