I'm a huge advocate for public transport, and as is typical in Europe, my attitude towards private cars in an urban environment is on the negative side. My opinion however, may be much more negative than most! To preface this, I have a driver's license, and I do see the need for some private car ownership and use within a city (for example, people with mobility issues or work vehicles), but cities almost universally have given far too much importance to the private car and not half enough to alternative forms of transport like cycling, walking, and public transit.
I've always believed that people will do the easiest thing over the "right" thing if there is any form of friction to doing the "right" thing[1]. In this vein, governments posit that they want to increase use of these alternative forms of transport, but haven't concretely made it easier to use alternative forms of transport instead of private cars, and so, all their "efforts" end up having unsatisfactory results. I think the problem is two-fold. On the one hand, the "effort" being put in really isn't substantial enough to actually make the difference expected, but secondly, the investment is just in the wrong place. An example of both of these in action was the boom in cycling during the COVID-19 pandemic. As widely written about, cities all around Europe allocated extra money towards cycling infrastructure, and there were so many people buying bikes that shops just couldn't keep up. While great on the surface, what has transpired is that the extra money and infrastructure was temporary, and all the new bike owners are giving way to the danger they are put in by poor infrastructure and reverting to previous habits. People will do the easiest thing, and in this case, that is the safest.
The primary reason that roads are so dangerous for cyclists are private car use coupled with this lack of cyclist-first infrastructure (you only need to look at Amsterdam's focus on infrastructure to see how safety should be done at that level, but how and ever). With the assumption that people cannot force the development of infrastructure from an unwilling government, what can people do? In my opinion, people need to assert their ownership of their city. A city-space is not, and should not, be designed for the speed of cars over the safety and comfort of individuals. One of the few examples of shared space are common bus lanes, meant to accommodate buses, taxis, and cyclists in the one lane of road. These are a huge benefit to cyclists over the alternative of fighting with all traffic, but they are constantly abused by entitled private car drivers to skip traffic, or by design in some cases where they are legally allowed to be used by private cars at certain times of day! Our cities would all have less noise and air pollution, be orders of magnitude safer, and encourage small businesses and green spaces all over if the private car was removed from them. The city streets would rightfully prioritize people instead of cars, and this is the reason I think people should walk in bus lanes (under certain conditions!).
You have more of a right to walk where you like in the city than a private car does. If you walk in the bus lane when there are no buses, bikes, or taxis around, then you are asserting to everyone who passes that this space could be used by people and it could be designed in a new way to maximize human comfort and enjoyment. It also has the added benefit of stopping entitled drivers from deciding they deserve to skip everyone in the traffic, which I'm sure everyone appreciates!
[1] I looked for a source to this as I expected there to have been studies done on this phenomenon, but I didn't find anything. Let me know if you are aware of anything in this area.