@tsarstepan,
Twitter lists are so you can get updates from people without following them. This is useful if you want to show that more people follow you than you follow (which makes you look like more of an influencer). It's also useful to have a private list for your competitors, for example.
I'm on a ton of other people's lists.
https://twitter.com/shrinkingjes/memberships
I'm on Massachusetts and Boston-type lists, writer lists, Quinnipiac lists, social media, etc.