I second this but it's not even about being the best of humans. At least 90% of amateur cyclists are out of my league and yet I insist to go cycling, because I like it.
Cycling is a very interesting example. Cycling was crazy huge for a while when it was the fastest form of individual travel (only trains were faster) and many people moved on when the internal combustion engine became practical. But the subset of the appeal that remained despite engines has been rather stable ever since.
In some places it's faster than a car, due to 1) the sheer volume of cars meaning that any driver will be stuck in traffic and 2) it being way easier to find parking for a bicycle than a car. I live in a city where this is often true.
That said, maybe the appeal that's remained since has been relatively stable overall, but locally it varies a lot depending on the cycling infrastructure that's available. More people ride when they feel safe doing so.
When I used to ride my bike to work, I literally turned a 45-minute drive into a 10-minute ride. Unfortunately, the weather in Illinois sucks so I couldn't do it year-round.
That's not what made people love bikes in that one short time window in the 19th century. It was the fastest thing, period. Bugatti Veyron fastest if you like. Hence the collapse when that ceased to be true. Even horses will outrun a trained cyclist only for very short distances (on longer distances it's roughly a tie even for runners)
That's why I wrote "individual travel" in my original post. The core of what I was getting at is that for many of those fascinated with the bicycle at that time the human powered aspect simply wasn't part of why they loved it. They moved on to e.g. motorcycles as if it was just the next stage of the same thing. Or directly to aviation, as a certain pair of brothers who ran a bike shop did, not before contributing a design tweak to bicycle technology that's still present, unchanged, in almost every bike available today including for example those that were used to win this year's Tour de France (and most likely every iteration before).
Horses outrun moderately trained cyclists only for a very short distance, on longer distances they fall behind runners. The main benefit of a horse is that you can carry more stuff with you.
Horses must be fed even when you don't ride them. Cars and bicycles stay where you left them and don't ask for anything. But I won't leave a bicycle parked on a street for a week.