The development of a game requires numerous processes and is not something that happens overnight.
Among them, single-player games are somewhat easier, as you don't have to consider as many factors and there's less need to worry about server-side issues.
Even if a single-player game has bugs, it's actually not that big of a problem; they can be fixed gradually later on.
But online games are different.
Due to the multiplayer connection aspect, both players and developers have a much lower tolerance for bugs in online games compared to single-player games.
For this reason, the development cycle for an online game is often not much different from that of a single-player game; it might be completed in one or two years. But for players to finally get to play the game, they might have to wait a long time.
Let me give you an example.
Two games with the same investment scale, one being single-player and the other online, are developed simultaneously.
