Wordpress (well Automattic) is a >1 bil company, operates about 1/5th of the websites on the internet, spawned a massive industry (and depending on how you slice it, also a subindustry) that provides jobs for hundreds of thousands of web developers and designers, and greatly shifted the nature of blogging and websites on the internet. So yeah, I'd say if there's a company that claims to displace Wordpress it's not unthinkable for it to raise hundreds of millions.

But what I find a bit silly is that Medium often gets held up as a journalistic enterprise when it's just a publishing platform, albeit a nice one.

Wordpress is software that displays a web site's content.