To add to my previous comment, it would become a responsibility of client applications to "handle lists better." Nostr needs to lay the foundation so clients can offer proper tools for managing these lists.

Imagine filtering by "people you haven't categorized yet." You could automatically see who you haven't sorted. You could quickly change the label of a group or split people into new groups. 

If you were using Nostr in a CLI, it's probably not very efficient. But that is a minority of people. The majority of us are using web clients. CLI tools could certainly be developed to handle lists better as well, if desired.

Twitter lists only list people using Twitter. Nostr lists are globally decentralized, unlike Twitter. I have a Twitter account and have never touched lists. I wouldn't even know they exist because I don't have a reason to use Twitter. I am sure I'm not alone.

The point is that Twitter lists can only scale to the size of Twitter. On a decentralized protocol they have more room, and reason, to scale.