I don’t know what a .webp file is but I don’t like it. They’re like a filthy prank version of the image/gif you’re looking for. They make you jump through all these hoops to find the original versions of the files that you can actually do anything with.
Of all the formats you mentioned these are supported on popular platforms:
That’s why gifs are still a thing.
This is circular reasoning. They are wondering why gif is still a thing precisely because it’s so supported while other formats that are better aren’t and you are answering that it is because it’s supported while other formats aren’t.
In that case the only people that can answer the question are the engineers from those platforms.
It’s called an industry standard. We’re using the same bolting in mechanic for ages. Only in computer science do things have to change every year…