Google introduced nofollow in 2005 to fight comment spam. Since 2020 it treats nofollow as a hint rather than a strict rule, so a nofollow link may still be used for crawling and, in some cases, ranking.
Sites often nofollow user submissions, paid placements, and links they don't want to vouch for.
Why it matters when you launch
Nofollow listings still matter: they send visitors, get your brand mentioned, and make your backlink profile look natural. Just don't expect them to move rankings much on their own.