Which won’t open in Photoshop 2021, or your parents notSoSmart TV.
Questions like: will you be able to open them in 20 years, does this version of ImageMagic supports it, are not things I’d want to deal with daily.
Yeah, thanks but no thanks.
Hard to compete with standards with expired patents and equivalent if not better performance when the other side is sponsored by a single company. Especially one not particularly known for long term commitment to their projects.
I don't think webp was ever meant to be an archival format, especially when used lossily. I wouldn't want a dithered blurred png to be the one archived image I have, either.
Typically I've seen webp served at the CDN or client, where a png or jpeg alternative is also available, and where (hopefully) the website owner has the original asset somewhere safe.
Between "now" and "nobody uses webp" anymore, it's still a super useful format to speed up pages for a majority of users. That doesn't mean you should rely on it to be a safe archival medium, but that's not the only consideration.
Of course nobody is going to force you to use that (or really notice if you don't). It's just one image format out of gazillions.
Webp does lossy compression with alpha, think photographs with transparent parts. Png can't do that lossily and jpegs can't be transparent.