In addition to what's above, it's important to think about where the money is coming from.
To be able to keep the server open and more importantly, pay the developers (which I think is a rarity anyway in OTS), you need to be continuously making money. Or at least getting donations, to put it mildly. The idea of making money on OTS is a long and heated debate but everybody recognizes there is a certain cost to running a server and it's only fair that some donations cover it.
However, recently we see more servers advertise their lunch for 2 weeks and then launch and live for 3 days until they get closed because there is no more players (and then money). Of course, the server owner could use the money to keep the server running, but what's the point if there's nobody online? They can just take the money and go. In fact, the expenses shift in time. Server owners start paying for server and advertisement weeks ahead. Let's assume they rent a server for a month and an advertisement at a well-known server list website. Then they launch in their third week when they have one week of server left and never renew it. They break even, most often. But there is no real RPG that continues. They reap as much money as they can.
Why is that? Like @J.Dre said, most players are <18 years old kids in school. They learned to have much higher requirements. There's more games struggling for their attention. It doesn't mean the other games are better games. Every year people hurry more and have less time. So they end up spending less time on every single game - it doesn't mean they play less overall! But the true gameplay of Tibia requires continuous dedication and time and interest to succeed (and enjoy). That's not possible anymore. So options are limited.
To be able to keep the server open and more importantly, pay the developers (which I think is a rarity anyway in OTS), you need to be continuously making money. Or at least getting donations, to put it mildly. The idea of making money on OTS is a long and heated debate but everybody recognizes there is a certain cost to running a server and it's only fair that some donations cover it.
However, recently we see more servers advertise their lunch for 2 weeks and then launch and live for 3 days until they get closed because there is no more players (and then money). Of course, the server owner could use the money to keep the server running, but what's the point if there's nobody online? They can just take the money and go. In fact, the expenses shift in time. Server owners start paying for server and advertisement weeks ahead. Let's assume they rent a server for a month and an advertisement at a well-known server list website. Then they launch in their third week when they have one week of server left and never renew it. They break even, most often. But there is no real RPG that continues. They reap as much money as they can.
Why is that? Like @J.Dre said, most players are <18 years old kids in school. They learned to have much higher requirements. There's more games struggling for their attention. It doesn't mean the other games are better games. Every year people hurry more and have less time. So they end up spending less time on every single game - it doesn't mean they play less overall! But the true gameplay of Tibia requires continuous dedication and time and interest to succeed (and enjoy). That's not possible anymore. So options are limited.