I'm not an advanced user of pdfs so I'm not sure if there's anything major missing from these, but either Okular or just the built-in browser ones works well enough for my basic needs of reading and the occasional form filling for the desktop, and on android I use muPdf.

Someone must put in the effort to make something. Should they not be compensated for their time?

When I was a Mac user, I found the built in Preview adequate to my needs.

It's still alive and kicking in anything government. Third party support for forms and other kinds of interactive stuff is ... lacking.

Well, you know what they say about assume...