Fitness and confidence is easily overtaken by stupidity and resentment by car drivers on the road, at least around here. The white spray painted bicycles you see along the road can attest to that.
Yet, the people who want bike specific infrastructure are perfectly happy with bike lanes that require that car drivers see you and react in 20ms when you suddenly cross their path. Instead of being in front of them with plenty of time, like you would if you were using the same road. For example, in Madrid there is such a white painted bike next to an intersection between the regular road and a bike path. The cyclist riding the bike path was killed when he crossed the road. Such a road design is just criminal: https://elpais.com/ccaa/2017/08/28/madrid/1503932795_982370....
As if bikes aren't suddenly appearing out of nowhere when they use the same road as cars? When there's a cycling path you'll at least know where they will be coming from.
The solution to that problem is not putting cyclist and cars on the same road, we've tried that and it's worse. The solution is separating bike and car infrastructure so that there are as less as possible crossings between roads and cycling paths.
Berlin just got 15 more of those bikes this year already (which is more than usual, maybe due to corona).
[1] https://en.wikipedia.org/wiki/Ghost_bike