It is a nice concept in theory. It has a bit of resemblance to the metaverse minus monetary enshittification, but there are some challenges to this.

It would for example end up just as dead if the other players got bored of it and stopped playing. Then there is server costs for something where there really isn’t that much realtime interaction in, and all these metagames would need to be just as fun with a global time at a set flow, or be OK with synching only at the end of the day.

These of course aren’t impossible challenges.

You could leave the “online” part to a simple global api backend and skip the gameserver itself to greatly reduce costs. You wouldn’t see the other players in person but you’d see their shops grow each new day, and there could be an NPC of their owner walking around.

You could bankrupt inactive players and give their lands to new players, and implement import/export costs for distant shops incentivizing local trade. You’d probably still want normal NPCs, but their interactions would have to be predetermined each day if you don’t have a game server running all day, and want to prevent cheating.

The implementation difficulty and cost greatly varies depending on how much interaction and fairness you want, but setting up an API server is fairly easy if you don’t worry about scaling in case the game really takes off.

Patent the code and sue Nintendo when they release the game.

Why not just use Matrix? I thought it was the goto FOSS and decentralized Discord alternative.