PDF generation

None of us here in the Community can speak as to why (?) Apple does anything. We are only other Apple users just like yourself.

But if you feel strongly about something you can leave product feedback or submit a request for features consideration in macOS or iOS or if you have other concerns using this link: Product Feedback - Apple

if you elaborate with more than "stinks or just doesn't work" the rest of us users can contribute as to if we experience the same challenge if we attempt to perform the same task on our system, or if it's unique to your setup.

You are posting in the Sonoma forum, but I am thinking that your question is probably about the iPhone. Am I right? There was no change in Sonoma, or Sequoia, or Tahoe, for that matter, as far as making pdf; and you mention "Files", which is an app for the iPhone and iPad (a poor man's Finder, so to speak).