There was a while when everyone was basing their company's official blog on Tumblr! The space is so bad people were using Tumblr for their official company blog!!
Then came Medium and for a while people rejoiced but then it turned into an annoying website.
Yea there are "many" blogging services but each one lacks some important things that make them "meh".
- You need to have a commenting system. A blog that is just a set of static pages is not so interesting. I suppose the hard part here is fighting spam?
- You must support non-latin languages. Sometimes I blog in Arabic and I want RTL support on my blog.
- You need an RSS feed and email subscriptions. Let people build up their audience.
- You need to support multimedia (images, movies, audio ..)
- You need to support input by several languages (markdown, html, wysiwyg)
- You need a set of decent looking themes and have them be somewhat customizable
- You need to be easy to setup! If you're a hosted service, this is often a non-issue, but if you're a "you host your own blog" you need to provide something better than "here's the source, now install these twenty different development tools and run all these commands here and there and edit these fifteen config files so you can build and configure your blog".
- You need to provide the user with a way to easily get all their content so they can switch away from your platform. If the data is in a special format you should provide them the tools necessary to export to various other formats (html, pdf, etc..)