Short answer: No.
Now, let me explain why.
World of Warcraft at its peak, around 2017, had about 46 million MAU. Even now, the MAU in WoW don’t go below the 500K mark, and that’s considering its popularity has been declining over the years. It’s still a very big MMO.
Another thing to put it in perspective is that it took Blizzard, a AAA studio, roughly 13 years to make WoW reach 46 million MAUs. Your game can become as successful as that, but it certainly won’t be overnight.
In terms of server capacity, there’s two ways of scaling:
- You get more powerful servers that can handle more concurrent players
- You split your userbase on different servers to spread the load across various servers. There are two ways of doing this:
- Sharding: Each server will be its own entity with its own userbase that will be always connected.
- Area-splitting: The userbase is in a single world, but you split it into different areas so every player is physically present in only one area at a time.
As you can see, there are different ways of solving this problem using an unreal server.
This is why my main point is this: The amount of time it’ll take you to develop a custom server is counterproductive to your immediate needs. It is best for both you and your players to have a functioning server now and let the game grow than to overcomplicate your development over a feature you might only start to worry about ten or eleven years down the line when your player base is in the dozens of millions.