On Mobile (using Mull) the PDFs are completely pixelated and simply dont render more details. Even after zooming in it takes forever.
Meanwhile on Desktop (Librewolf, Firefox, … on Fedora) it seems a bit slow compared to Okular, but it is very fine.
could be that, but all i see is the page with the big blue download button (which is slightly grayed out and not working) so idk. anyway, i found in this posts thread a good pdf reader so i wont need the browser extension, thanks though