Adobe also has an order of magnitude lower number of installed software than Chrome or Firefox which makes patent fees much cheaper. And their software is actually paid for by users.
Not that simple. Maybe they struck a deal with a few of the companies or they made a different risk calculation. And of course they have a pretty fierce patent portfolio themselves so there's the notion of them being able to retaliate in kind to some of these companies.
I don't think that's true (see my other comment for what the patent is really about), but even when it is, Adobe's adoption means that JPEG XL is worth the supposed "risk". And Google does ship a lot of technologies that are clearly patent-encumbered. If the patent is the main concern, they could have answered so because there are enough people wondering about the patent status, but the Chrome team's main reason against JPEG XL was quite different.
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.
Adobe included JPEG XL support to their products and also the DNG specification. So that argument is pretty much dead, no?