I think it makes navigation harder for me; I notice that it's a lot harder for me to parse out actually relevant information in busy spaces like airports/cities. Particularly while doing something like driving, because I'm juggling a lot of information in those situations and paying more attention to the people around me, rather than just focusing on signs.
For a long time I thought that was all just due to crowds/stress and nothing else, but I'm increasingly convinced that part of it is just that it's harder for me to pick out when scanning a room where the signs are the indicate where I'm supposed to be. Also seems to make it more likely that I'll walk past an indicator or miss something while I'm trying to navigate the space. I'm always paranoid inside of these busier spaces about whether I'm going to miss something important and end up walking in the opposite direction of where I need to go.
It may depend a lot on not just the area but also what you're personally used to; navigation in these spaces are a skill that people get better at over time. I suspect that some of the difficulties become less difficult as people's brains get better at filtering things out or recognizing indicators that they need to zero in on. In the same way that after a while playing a game you start to instinctively zero in on certain UX choices or indicators in a level, people also instinctively start to zero in on how a city indicates important information (is the sign always green, does it tend to show up in a specific place). So this might also be more of an early-user UX problem for people who don't go into the city all the time or who are particularly susceptible to getting distracted by motion/colors.
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There's a lot of research that brains are really good at learning to filter out advertising; part of the arms race in advertising isn't just with ad blockers, it's figuring out how to present ads in increasingly unusual ways where your brain won't just do pattern recognition and literally just refuse to process or register them. Human brains are heckin good at pattern recognition.
But that means that there is an arms race with advertisers trying to figure out what the next evolution is with billboards or how to trick your brain to register things, and it means that people who are less equipped to do that filtering or are just unfamiliar with the space often end up getting thrown in the deep end because their brains aren't trained to do that filtering yet, or are trained to filter different things.