Well I agree to focus on Nostr's points of leverage, and not needing to name Nostr at the time you try to cross the chasm. But, I don't see any reason to pull punches, so if you're not pointing yourself at a $bn+ competitor incumbent then I would say you're aiming small. The benefit of aiming big instead is you're not taking any business model risk, you get to simply copy and incumbent and be a fast follower riding better rails.
Discussion
Think big never hurts, but when you look at what Okta alone does, for IAM and the rest, a nostr equivalent (if you want to call it that) offers like 1% of that (and maybe with millions in investment in a nostr-based Okta then 5%). Sure with nostr you get bonus things that Okta can't do, but the things you have to give give up are non-starters for business.
The same for slack, nostr is just not an architectural basis for a piece of software that can do what Slack does, and giving up these things that Slack does again is a non-starter. Nostr at best can augment these platforms by filling in certain gaps or serving certain niche demographics.
For a reality check, the closest thing to Slack on nostr is chachi.chat.