Comment by cosmic_cheese
17 hours ago
From the standpoint of a layman it looks like there's a lot of overlap between writing safe web browsers/engines and writing safe PDF readers/engines. There just hasn't been anywhere near as much of an impetus to push PDF readers/engines in that direction because most of us aren't interacting with PDFs nearly as often as we interact with the web (and things built on web tech).
The difference is that web browsers absolutely need to support JavaScript to correctly display many important web sites, whereas that’s not necessary for PDF. You also don’t have to deal with vulnerability footguns like XSS/CSRF/CORS in PDF. Except for some rare special use cases that PDF viewers don’t need to support, nothing has to happen online for PDF. It’s really not comparable.
Most web browsers actually make decent PDF viewers by default don't they ?