I was just wandering if it was easier to make a Survival Mmo compared to a simple Mmo.

Not really. The gameplay theme and mechanics are not the generally the hard part, the hard part is the "massive multiplayer" part. Certain kinds of gameplay may lend themselves to allowing certain solutions to the scale problems being more appropriate, but fundamentally I don't think these move the needle on the total amount of complexity involved. And none of them address the difficulty of actually acquiring enough players to test and prove that scale.

The "massively multiplayer" part of MMO was created to show the difference between regular online games.

Back in the late '90s when it was coined, Massively Multiplayer meant servers with over 10,000 concurrent users. The normal notation is "C" for "concurrent" followed by the number, so in this case C10K.

Today the number for MMO is usually much larger, C100K or so at a minimum.

Building an online game with a small number of concurrent players, maybe 4 or 8 or even 64 (C4, C8, C64) is relatively easy. They can usually connect directly to each other, or go through a game hub you set up and control. You can do this in your basement or through a cheap hosting account with pocket money for budget.

Controlling a larger online game (still not MMO) with many concurrent players, say C1K or C2K, that requires an investment of dedicated hardware and probably multiple data centers. This generally requires a multi-million dollar budget and commitment from a developer.

Controlling a massive number of concurrent players, C10K or C100K, you are looking at price tags in the hundred million dollar range.

Unless you happen to be a billionaire hiring a very large team for their dream game, building an MMO is not feasible for an individual.

Market saturation seems to be too big of an issue for new MMO's to launch properly. It seems like every new MMO that launches has less and less population than the last, and that population bails quicker.

Instead, you should focus on trying to make 1k~ CCU profitable and sustainable. Possibly even fewer.

You might want to consider a MUD - Multi-User-Dungeon. These are games which are very light on resources and are meant to host only a few dozen players.

You'll need to learn how to code - that's the toughest part!

If you are not an expierienced dev, forget about making an online game.

If you are not filthy rich or head a big studio, forget about doing an MMO.

Given that none of the above is true in your case (If one or both happens to be true for you, feel free to ignore my advice), just learn to create single player games first. Networking is about the hardest part to get right in game development, and all the other parts will already take years to learn and create. Learn to program, program old classics (pong, tetris, ...), learn to use a modern game engine, start doing small 3D games, release a game, then think about doing an online game. In this order.

And while doing that, a) make sure you can pay the bills, and b) make sure you have enough free time left for work/life balance. Let me tell you, all of that WILL fill years of your life before you should even start to think about doing online games, let alone an MMO.

Babysteps, man, babysteps.

About "is it a good idea": No.

Doing an MMO at the moment is a pretty bad idea. Are some big studios still doing it? Yes, of course. Most of them have given up, because they sunk millions into failed MMOs in the noughties. So many WoW clones have come and gone, some tried to survive by going free to play.

Most "MMOs" coming out today are "poor mans MMOs" that don't really try to fit 1000's of players into the same instance... they are glorified Matchmaking servers with a kind-of persistent world feeding players into normal 30 or 64 player matches.

Not that exiting, not MMO at all (Save the persistence if you call that MMO)... but seems like a compromise to keep cost down, and players do not seem to care.

Lesson 1: not everything that is called an MMO is an MMO! Make sure you do not use the monicker in a wrong way or you will face a lot of negative response for no reason (an MMO is seen as being pretty much impossible to do for a single dev, an online game with matchmaking is more achievable though, and your "MMO" could be just that)

Lesson 2: there is a time and a place for everything, and now is not the time for an MMO, and little space left for a new one! At least if you plan to do anything "traditional" (or, putting it more harshly, are copycatting the others). That might change once WoW has lost its last player, but that will most likely still take years... and if these players leaving the biggest MMO left will be in the market for a new MMO is highly questionable. It is very well possible that the WoW-leavers leave MMO playing for good, and what newcomers look for is not so clear yet. Maybe VR will give MMOs a new lease of life, maybe the fact that lots of big studios burned their hands doing MMOs will leave a big niche for some years (big companies are always oil tankers when it comes to reacting to the market).

Still, do extra market research before developing a game as time and resource hungry as an MMO.

Lesson 3: don't try to run before you can walk! Learn game development, then come back asking for online game development. You will be taken much more serious.