In OSM, it's difficult to say something is forbidden when the wiki allows different solutions to the same problem.

The topic of pedestrian and cycle paths has been discussed many times in various discussions, but the most relevant thread for the Tricity area is here: https://community.openstreetmap.org/t/mapowanie-ciagow-pieszo-rowerowych-w-aglomeracji-trojmiejska/120463

I don't know what you expect from this discussion. Basically, a lot of time can be wasted arguing over and over again about the superiority of one solution over another, and everyone will likely stick to their own opinion.