In my cycling club, when we plan events, if we know there will be this many cyclists we work with police and close the roads. This is the last one we did: https://www.youtube.com/watch?v=x-Kfz9S6h4M You can check out the security measures. And we're just a local club. We do things like this about 3 times a year. Other local clubs do the same. Having as many cyclist as in the video with no security is amateur hour and it's irresponsible. My guess is they know this and they are doing this on purpose as a form of protests or something
So, nobody should cycle from village A to village B, ever?
In Spain the minimum velocity is half of the speed limit so a car has to go at least 45km/h on 90km/h road. Going slower than that causes dangerous situations. Bikes have to go on the shoulder and I don't think that's safe or responsible. I can get to all the villages using secondary, 60km/h roads.