Earlier quoted context omitted.
Moq, lots of PDF libraries, Avalonia, Automapper, MediatR, MassTransit,Telerik stuff,etc. I'm not inherently against it, we have a problem with opensource being asymmetrically underfunded and if people going commercial is the cost perhaps we've failed.
There are a few non-paid PDF libraries, but that is the biggest pain point in .NET, anytime you need advanced features for PDF, you're better off paying for a license (it's just insanely expensive unless you're a large company). Having worked on some basic parsing of metadata from PDF spec, I would rather pay than have to code something myself. PDF is such a PIA.
libqpdf also intentionally limits its scope to PDF structure, so doesn't address nontrivial content creation or manipulation (page content handling is pretty much limited to compressing/decompressing and parsing/unparsing the content stream).