I'm not saying anything about building an audience for a blog, only that Twitter is useless for nearly everyone. The massive engagement boost from one retweet is meaningless in terms of building an audience or having an impact outside of that tweet. A blog can get indexed by Google and bring in folks ten years from now. Tweets, in contrast, have a lifetime of a few hours and then they disappear into the ether. I'd much rather have a post hit the front page of HN than get 50 retweets (which would be in the extreme right tail of all tweets).

This is untrue, tweets are also index into Google (just not as rapidly) and tweets often resurface via images. Many Twitter moments are reminiscent by users via retweets or screenshot posts.

Authors often retweet their own post and even pin them to increase their longevity, giving a tweet a much longer shell life for engagement than a hyperlink.

That’s not to mentioned when the tweet is shared on other platforms like HN and more noticeably Reddit.

I agree with your comments, In blogging its your own like you own the content plus its for the long term.

both platforms have many writers that are successfully building an audience