As @jkp says, right now it looks like both. 
The vast majority of smartthings customers do not have a hub. That will probably continue.
A very small percentage are power users, who want a multi protocol hub. That’s the majority of the people on this forum, of course.
And then it feels like there’s likely to be an in between group, maybe the people who currently have a Philips hue bridge and a Samsung smart television. And they read about matter and want to add a few devices. And Samsung has just introduced the Station for them.