How people access the Web
In 2025 it is my contention that most Internet users access the Web using a mobile device (this is kinda stating the obvious)
Presenting reports in PDF format
Uploading a PDF to a website is the easiest way to present a report. All you have to do is provide a link to it and then the browser does the rest of the work. This is why there is a problem as there are things that are not ideal here.
From the webmasters point of view the access of these reports can only be seen as server log entries. It is not easy to track using say Google Analytics. From the Internet users perspective it depands on what device they are using to access the report. An iPhone will render a PDF in a much different manner to a Windows computer accessing the PDF in Microsoft Edge.
I have experimented in displaying PDFs in an iFrame.