Your point is super important, but fortunately there is actually a lot of research and debate on this topic. The most common misconception is that it's enough to talk about the absolute total length of cyclable paths, but I simple to understand that's not the best metric to compare cities.
I'm the designer and developer of CicloMapa [1], one of the tools presented in the video. The project is a partnership with ITDP, which is an international organization that created and constantly measures a metric called People Near Bike (PNB) [2]. In summary takes into account if the infrastructure is really serving people that live nearby.
Another metric we use, at least for some brazilian cities, is IDECICLO [3], which analyses the quality of the existing infrastructure in terms of access, comfort, safety etc. It's a very holistic metrics, but compared to PnB is way more complex to measure and more prone to subjectivity.
[1] https://ciclomapa.org.br/ [2]https://itdpbrasil.org/pnb/ [3] https://plataformadedados.netlify.app/ideciclo/