I've been having this debate with a couple of the guys in the office who have bikes or, would like a bike to just commute on as ever restricted parking, increasing traffic jams are beginning to take their toll but, are not concerned about the effort of cycling but more about not being able to keep at a reasonable pace causing a danger to fitter/faster cyclists and causing drivers to get even more irate. Additionally our new offices do not have showers so that a downer.
I used to ride my commute route almost 20 years ago for 1 year on a road bike. Even compared against my motorbike at the time, I was barely 2-3 minutes slower, from A to B over 4 miles, despite me speeding on the motorbike. On the odd occasion with tail wind, flowing run I matched the motorbike's time. The car's time was easily matched (usually a tad quicker) with the advantage of not wasting time finding parking and then walking etc. Admittedly, I was riding flat out to achieve this but, was able to do so back at that age and high level of physical fitness and strength. Since my knees had issues my running and football for cardio came to an abrupt halt 9 years ago and I've just been doing gym instead. I am taking advantage of the quieter roads at present, to get my cycling fitness and performance better but, I'm genuinely intrigued how an e-road bike would compare. As an example, my Trek ALR is a great road bike but, my Giant Propel oddly glides smoother, maintains its speed easier, more responsive and tangibly quicker for the same effort. I do not like to knock something without trying but, I am certainly going to see if I can get a test ride on an e-road bike back to back with my normal road bike to see what the real difference is. After a real world test, I may just seriously consider an E-bike if it makes me feel more confident to tackle my commuting needs/wants. For me there would need to be a serious advantage in the real world, over and above boosting my personal cycling stamina/performance as, E-bikes are hideously expensive, maintenance costs and complications will also rise as and when stuff breaks or one fancies upgrading bits and bobs.
Some people are just down right lazy and yes, full electric propulsion with no effort is their ideal but, as mentioned by many posters, there are some great uses for e-bikes either fully or partially propelled and they play a vital part in the evolution of cycling in my opinion.