Adobe sells paid products and can carve out a license fee for that, like they do with all the other codecs and libraries they bundle. That's part of the price you are paying.
The same thing can be said with many patent-encumbered video codecs which Chrome does support nevertheless. That alone can't be a major deciding factor, especially given that the rate of JPEG XL adoption has been remarkably faster than any recent media format.
Is this not simply a risk vs reward calculation? Newer video codecs present a very notable bandwidth saving over old ones. JPEG XL presents minor benefits over WebP, AVIF, etc. So while the dangers are the same for both the calculation is different.
Harder to do for users of Chrome.