WordPress.com didn’t even allow plugins until ~6yr ago, so it really wasn’t a meaningful option for serious sites —- aka sites with money. It was a predominant blog hosting site for a while, but there isn’t as much money in that market. Other WP hosts have gone after more lucrative types of sites which need something more.

My point is that Automattic was successful for a long time without being the dominant host (at least in terms of money per site).

Honestly, I don’t get why Ghost must be the dominant company in the space. Sure, it’s a bit of a zero-sum game, but not so much that literally every other company in the space must die if one becomes more successful. If that happens, it’s just an impetus for other companies to adjust their approach.

You don’t need to grow so massively big to be able to compete. You just need a better product in one specific area that matters to enough customers, and you can do that sustainably with a small team.