Flyby only shows Strava users who set their activities to public. I see lots of folks on the road whose rides don't show up on flyby. They set their activities to friends only or private, unless they're going for a PR or KOM. Most of the local pros, when their team was active, didn't set their rides to public. If they did they'd dominate every local KOM. The rest of us mere mortals who crack the top ten are enjoying a comfy delusion, thanks to the younger pros and serious amateur teams who don't set their activities to public.