Those pro road/track cyclists really should take note of this !
To the limits of accuracy of Strava (yeah, uh-huh, that accurate)… for my commute I’ve swapped and changed between flats and clips, between a 20 year old junker training frame with downtube shifters and “relaxed” bearings and a modern day carbon Di2 loveliness.
Conclusion… the difference, if any, is a small number of seconds, usually not relevant compared to how the engine is operating on the day. It is not about the bike. Surprisingly, it isn’t about the pedals either.
Humble brag… scope of research includes top 10 placings on heavily contended segments between 19s and ~4 minutes.