Around half to a third of the e-bikes I've seen are illegal even under Class 3's limit of 28mph. I can catch and draft 28 on a road bike quite easily. I know exactly what low 30's looks like too. I've failed to catch people even with a tailwind when they had to be doing nearly 40mph. For reference, the fastest I have continuously pedaled on flat ground, came from a red light changing as a city bus was getting up to speed slowly on a long stretch of Pacific Coast Highway I dropped in and held 55mph plus for several miles in that pocket. An e-bike draft is not so efficient, but catching is not a problem even just a little over 28mph.
I bet this regulation is due to the wheelies idiots playing chicken with others.