Look, the digital video world exploded, 90% of it using MPEG's standards(MPEG1/2 to start with, h.264 now. HVEC/av1 is just a blip) they were all patent encumbered
FFMPEG runs 60% of the digital media world. _if_ patents were to be called in, places like disney, netflix & fox would have to spend literally billions swapping out FFMPEG or licensing it.
Your phone/computer pays a h264 tax, in the same way that they pay ARM/intel, qualcomm, wifi alliance, HDMI alliance et al.
HVEC gives you more efficient 4k, and HDR, but for most people that just isn't important. Streaming services still use h.264, because there is not hardware/software support upstream.
Now, the thing that will decide it is the speed/quality/cost tradeoff. If the hardware doesn't support a codec, it won't be used.
AV1 has a really slow encoder, so until that has changed it's not going to be used for on-the-fly encoding (live or just in time delivery from mezzanine codec)
for industry noise, see https://www.ibc.org/delivery/codec-wars-the-battle-between-h...