Is there a version of Firefox that removes this bloat?
Given that Mozilla is very resource constrained, why are they working on features that aren't necessary?
I think Mozilla's line of thought here is that PDF documents are widespread in the web, to the point where they are a de facto web document type. So it makes sense for a web browser to support them rather than calling out to a user's desktop program (though I assume you can configure it to do so instead).
There's probably a bit of "our competitors do it, so we have to too" in there as well.
And I also like that I can preview long-form PDFs in the browser, before choosing whether to save them and read them “for real.”
Imagine if every time you opened a direct-linked JPEG image in your browser, it treated it as an attachment, downloading it and opening it in your external image-previewer app, rather than rendering it as a synthesized HTML DOM wrapper around the image. Wouldn’t you be annoyed by how cluttered your Downloads directory would get with random files you never actually wanted to save?
And the reasons for not requiring an outside PDF reader are major: It's yet another likely-to-have-vulnerabilities program people need to install, then update. In most cases, avoiding Adobe programs on your PC is a good way to avoid a lot of vulnerabilities.
Chrome/Chromium uses PDFium, not PDF.js, so no. Not sure about Edge.
PDFium has been able to fill out forms for a long time. What’s new for Chrome is the ability to save edited PDF (as fillable).
However, I was able to confirm that Edge uses extension ID mhjfbmdgcfjbbpaeojofohoefgiehjai to render PDF internally[1], same as Chrome, so indeed it's using PDFium.
[1] The rendered PDF element would look like
<embed id="plugin" type="application/x-google-chrome-pdf" src="..." stream-url="chrome-extension://mhjfbmdgcfjbbpaeojofohoefgiehjai/..." headers="..." ...>
Having a sandboxed PDF viewer that works 95% of the time is great. For those 5% circumstances where I am actively trying to view a PDF and it won't work in browser, I'll gladly go through the minimal effort to open it in an external viewer.
I don't want to start explaining to my mother, over the phone, how to install and use the pdf viewer anymore :|