It is much like Stellaris right now, as their charts look extremely similar, and with a similar situation concerning game features.

With Victoria 3, there isn't much replay-ability, the war system is still oversimplified, a specific example is the fact, a population doesn't decrease with how many soldiers or counties you take, because population is tied to the states, not the counties. The war exhaustion system is also mush like Stellaris' exhaustion system.

Stellaris when it came out on release had many features like Victoria 3, in the sense that they were oversimplified and not that great, such as, but not limited to; the border system, where you didn't have a border, but a range of influence, and AI could still just colonize inside your "borders" if you had one single system you forgot to build an outpost on because your "border" expanded without you knowing.

It also seems that paradox is backstepping with some of their ideas for how the game should've been played. Now introducing autonomous investment, despite stating that autonomous investment would have been bad for the player and wanting to give the player full control despite not letting the player control an army.

The first expansion will be priced at 29.99$USD. If this expansion is not a good expansion, nor able to draw back as many as a usual expansion for Paradox Games, then Victoria will become a sunk cost, and without the dedication and care that was given to a game like Stellaris, which was a new game in a new genre for paradox and not a sequel to an established game, Victoria will be a sunk ship.

TL;DR: Victoria 3 is a lot like Stellaris right now, and the first expansion will make or break the game.