The truth is – it simply shouldn’t matter. If it works for them (or us), why should it bother you?
Some drivers wear lycra, or other silly clothes.
Some pedestrians, especially runners, wear lycra, or other silly clothes.
If this is still a problem for you, then we hope you can get over it.
Some cyclists wear “normal” clothes, because they are practical for the trips they are making. Others wear road cycling gear, some of which is made from lycra, because it’s practical for faster sports cycling. That’s really all there is to it!
It really really doesn’t matter what you wear. The same goes for safety gear, unless it’s actually proven to be beneficial, which car seat belts are.
All that matters when you are out and about is that you respect others and drive, walk or ride safely. If you can’t do this, please stay at home in your trackies, your pyjamas, or whatever else you want to wear at home. Nobody cares!