I’ve been clipped-in since the 80’s and still riding the same style = original Look (and knock-offs). So, I’m a biased input and only a road rider, no mtb biking.
I find 2 advantages on my newer road bikes:
1. spinning circles faster than 70rpm.
2. climbing hills/mtns
I also have older road bikes, some with toe clips and straps which allow for ‘regular’ shoes. That works for me, too……just not as comfortable for pedaling much distance.
edit: Perhaps unrelated, perhaps not. I have absolutely determined that the shoe you wear can absolutely influence the number of looks, smiles, passing nods/waves. Especially from the female cyclists (not so much the men) - these oldies do the trick for me.
Spin fast and the scars don’t show much