What is the point of porting it to unity for it to look exactly the same?
As someone that messed around with the EQ emulators, I can say that I see a huge benefit to them porting the game to Unity. The fact is that all the emulators were doing is emulating the SERVER side of the game. They were highly limited to what and how you could change in the game based on the specific client the server was coded to interact with.
With the game being completely in Unity (both server and client), it is essentially a 100% departure from any EverQuest code. If you want to add a brand new class to the game with unique abilities that don't exist today in EverQuest, you can do it.
With EQ Emulator, you had to pick an existing class in the game, and modify it as much as the game client would allow. For instance, using a monk as your base class to make a new class in EQ Emulator would be problematic because monks don't have nor regen mana. Then on the other hand, if you used a Shadow Knight as your base class, you couldn't use things like the Feign Death monk ability (not the SK casted version, but the actual monk FD ability) because that was specific to the monk class. There were ways to fuck around with it to kinda get what you wanted, but it was limiting and lead to a lot of crashes of the client. Straight up, it's a hassle to make unique game play in EQ Emulator. People do it, but it is a fucking nightmare to do.
As for why they are using the game assets of EQ in the Unity engine, that's purely cosmetic preference on their part. You could scrap every bit of the graphics in the game they make in Unity, and put your own assets in with what ever level of detail you care to spend the time making. In other words, it looks blocky because the objects they are porting in to Unity are blocky objects from EverQuest. They can be modified, replaced, etc with any level of detail you want, but the initial set of assets they are using in the port are those from the old EverQuest trilogy release.
You could literally take their game (if it was released in open source code form), pull it in to Unity, and replace the human character model with a human model from a modern day game if you wanted. The game engine isn't stuck with the low polygon count graphics you see in the screenshots. Unit can handle everything from low polygon to high polygon and everything in between. That's the point. The Unity engine is flexible and being upgraded all the time.