1 - owning your blog is too big of a barrier of entry, there is a need for a platform: look at the success at medium for tech writers, despite that we hate it.
2 - we need the return of the domain name based blog. This helps with independence, censorship, and the like. You can always move from the platform, and the platform can claim they can't censor you since it's your domain, so DMCA should be sent to you directly.
3 - this platform should do blog + microblog. You don't always have something long to say, announcement, though and quick tips are very well suited to tweets. But only this format leads to quality deficiency. Being able to write a big article easily is equally important.
4 - forwarding all posts to your social networks is essential. Yes, your blog should be the original source (so you get ref, credit, independence and not the duplicate content ban from google). But the discovery problem cannot be solved easily, and those networks already exist.
EDIT: unrelated, but I love phone calls. I mean, I hate doing them, but I love having the ability to do them. It's a universal reliable tech, it works in the country side, it works when the wifi is down, it works well in the car, and I don't have to have the app du jour installed or insist that the other party does.