I am using Firefox since the early 2000s and always stuck with it. The app is great in many ways but very often I have PDFs that are displayed in the browser but that just can’t be saved/shared on iOS. Either they are considered a „blob“ file in the iOS share dialog or the PDF is a saved/downloaded but then can’t be opened in the „files“ app for example. Since PDF has been around even longer than Firefox and since it is such a core doc format this really is a constant pain point for me. Because the mentioned files/websites always work in Safari.