Ask HN: Can AVIFs replace JPEGs inside PDF files?

Many news and magazine subscriptions use PDFs to distribute their content. The images are usually of JPEG quality. I assume this is so because the ancient JPEG is the underlying, embedded image compression format. (I believe above some version of PDF, JPEG2000 can be used too - but in my examples I see no evidence of its less blocky compression abilities in use)

Hence: Is it possible to use AVIF images inside PDF files, for better picture quality and better bandwidth use?

Thanks for your answers!