the primary objective of Twitter should be to create a medium that is attractive to advertisers.

which is what is really missing in every HN discussion of how you could rebuild twitter in a weekend.

that's only if all you see is the front end which is users talking to each other.

the backend problem of making advertisers happy is a whole different issue, which is a large data warehousing / analytics / reporting / billing problem.

and then there's content moderation, which is both demanded by a large subsection of users and advertisers and by political regimes that you operate under that you can't opt-out of.

and the content moderation task is made harder by the technological war with the 'bots' which requires backend tooling.