This isn't far off especially if you count on-CPU decoding. MPEG2 is sensible for the time, but can't scale to larger pixel resolutions or lower bitrates well.
The generation after MPEG2 (VP7, MPEG4 ASP, Theora) though, pretty much sucked universally and there was no good reason for it⦠second-system effect?
There a good modern comparison of the formats?