VP8 was patent encumbered.
Nobody knows if VP9 is but it is highly suspected to be.
AV1 won't outperform H.265 when there is no hardware support for it. That's the whole issue here. AV1 is dead when you have major platforms not supporting it e.g. iOS, OSX, PS4, XBox and almost every photo camera.
> Nobody knows if VP9 is but it is highly suspected to be.
{{By whom}}
VP9 is out and widely deployed now, yet no patent litigation has ensued. Meanwhile, there are now three patent pools demanding license fees for HEVC, with the latest one appearing just months ago. If you fear litigation, one option sure seems a lot safer.
AV1 won't outperform H.265 when there is no hardware support for it. That's the whole issue here. AV1 is dead when you have major platforms not supporting it e.g. iOS, OSX, PS4, XBox and almost every photo camera.