Fundamentally, I like webp, but display considerations have to be accounted for. Irvanview64, with all the plug-ins installed, still doesn't play webp for me, and if I transfer images to my phone, I'm not sure how they'll display there. I asked r/firefox on reddit, and this extension got two quick recommendations. I tested it on Vanity Fair and the images I saw in webp were now jpegs. It works, and that's all I can ask for.