I learned about 'serious' riding in college when I learned and acquired a very smooth pedal stroke by training on old-school rollers without any sort of support. Mash too hard and you'd fly off the front. try to throw the bike side-to-side like you'll see riders do in a sprint and you'll fall off the side. It actually helped when I practiced taking one hand off the bars to shift (downtube shifter) or grab my water bottle -- and not wobble. I even rode rollers using NO hands. That smoothness and balance have stayed with my in the 42+ years since! That same smoothness and balance result in less wasted effort, making for longer- and more enjoyable rides!

I tried cleats back in the day and hated them. Never tried spring-loaded SPD or any such retention system since I'd require shoes for same. Forget that!!

Yes, I wear touring shoes when I ride. Never do my feet 'fall off' a pedal if riding my bikes equipped with platform pedals. The rest of my bikes have either toe cages and loose straps or just half cages.