Somebody still has to do the city-wide politics. This with per street politicians could work, if they functioned like aides, but… then they would be aides.

Also, if there was one politician representing my street, and he is aligned politically very differently than I am, then I’ve got zero chances of getting the city to hear me. If I want less houses but much taller, and the representative wants single-family homes, me having an idea of how to make it possible to build one more tall house on my street would just crash into my street-representative’s political opinions. Now I can contact a politician that thinks the same was I do about what is good and what is bad. I can write them an email. They won’t read it, but someone in their office will, and then it will have an effect on the politician’s work. Depends on the politician, of course, but that’s something I take into account when choosing whom to vote.