I don't know if people remember the fraught Codec War of 2014, but the choice of VP8 and H.264 both being "Mandatory To Implement" was the compromise that the IETF reached, despite much opposition from both sides.[0]
As often happens with wars, though, the outcome in 2014 wasn't enough to permanently settle the matter, and there was a further outbreak of fighting later between VP9 and HEVC. More recently, some are saying[1] that the Codec Wars are back, with the arrival of AV1 as a contender.
For beefier machines VP8 works great, and you don't need to worry about cost. For IoT/Embedded space you usually just get H264 (from a hardware encoder). If we didn't have both I think it would shut out a lot of interesting use cases.
IMHO it would've been better if they specified some clearly out-of-patent and also simple-to-implement codec like H.261 or MPEG-1 as a minimal requrement.
I understand that backwards compatibility is very important, but this adds to technical debt.