And it likely won't come back because of the lack of support for 10bit channels needed for P3 displays. Jpeg2000 (Apple's alternative to webp) does.
WebP on the other hand is a proprietary format developed by a single company, an implementation of which is made available under an Open Source License.
So yes it's patent-encumbered but no more patent-encumbered than WebP.
https://chromium.googlesource.com/webm/libwebp/+/master/PATE...
On the positive side, it's now old enough that some key patents (e.g. arithmetic coding) have actually expired.