Kind 30000 lists is far superior to organizing users vs kind 3 followers if you want to attribute general categories or some context to npubs. I've been doing this for over a year and only use the simple follow list as a queue for npubs I need to assign to lists. But there's a tradeoff where more apps support follows and if you're an ideologue about web of trust, that's also based on followers without context.

The best list management tool is Gossip for the desktop. Any lists created there you can use in supporting apps like Amethyst, Nostrudel and Coracle.

You can also add and edit lists in Corny Chat but you need to know the npub (copy/paste) as I haven't built an index lookup yet. Listr also let's you define lists but is opinionated about kinds.