I am not an expert on the topic at all. My problem with the format is practical, it sometimes gives me trouble when saving, editing and sharing such images. Sometimes I couldn’t download and sometimes I could not open pictures of the format at all. I can´t tell you why exactly though but I guess those were probably caused by compatibility issues between certain browser and app versions and this relatively new format. I don´t say the format itself is bad but the compatibility issues can be annoying and I never had such with jpg or png. Also, I just googled for a minute and a large amount of people including many developers, seems to avidly hate webp for all kinds of reasons. Greetings go out to @JohnnyEnzyme