I often collect general information about a city for historical background about the area and the times. Discussions of elections and other political goings-on will often refer to how the city voted by Ward. Presumably voter registration lists would be arranged by ward also. I discovered that one of my research subjects was elected as an alderman; knowing the Ward information for all the families tells me at a glance who was in his ward, and who wasn't.
Would this solve some other genealogical problem? In a large city, it might help you separate individuals with the same name. The usual way I discover that I need a particular bit of information is to stumble upon a scenario where it would be useful to have it, only to find that I didn't record it, so I have to go back and look at all my sources again. So over the years, I have leaned toward recording more information rather than less. You can't always know in advance which random bit of information will be the key to unlocking a problem.
Check Google Books, Google Scholar, the Internet Archive, Hathi Trust, JSTOR, and other history / scholarly sites for books that will give you general background information about your city of interest. Town books can have titles like Municipal Register, Annual Report, or similar terms. You can also search for your town's name in WorldCat to find items in a library near you.
Don't forget to look for maps which show the ward boundaries!