There were plenty of discussions about life support on this forum already. From my understanding, community is currently divided in two major groups. First one argues, that life-support will be a cool mechanics to add into the game, and another argues, that it's not necessary. The major disagreement between these two groups lies in will life support be too complex to have. But the thing is - complexity of life support is almost entirely depended on the way of implementation. There might be countless amounts of parts and resources, required to keep Kerbals alive, which truly might be too complex, and might be just a single part called life support with only 2 resources inside - oxygen and snacks, that drain over time, which is no where near "too complex". My point here is, that there is no reason to argue whether it will be too much for the stock game or not, while we have no idea of the shape on life support, that will or will not be implemented into the game. I want you guys to think about it from a different perspective and be open minded.
While discussing possible improvements in KSP 2, a lot of people have talked about how sending a manned missions before drones makes very little sense(i'm talking about the missions that are at least "get to orbit" complex). I agree. Original Kerbal Space Program does not represent the level of complexity included in manned missions, compared to unmanned ones. There was no point in sending reconnaissance and testing missions to your destination.
First reason for that is, that all the information about celestial bodies, necessary for the missions, was already available in the Tracking Station. It can easily be solved, by removing all the info from tracking station, and integrating process of collecting said data into the progression system. Necessity of observing the Mun(or any other celestial body) with telescopes, researching acquired data, in order to calculate size/mass/orbital velocities, and sending probes to it, in order to clarify data, instead of blindly sending Kerbals roughly in the direction of the Mun(or any other celestial body), without any idea what will happen, should be essential and even fits well with the concept of progression system through missions in the "Adventure Mode" PC Gamer article talked about.
The second reason was, that in KSP 1, in order to send manned mission you only need 3 parts. Crew module, fuel tank and the engine(You don't even need the parachute these days! Every Kerbal has his own!). For the unmanned mission however, instead of crew module, you need drone core. But that's not it. You also need a power source, to keep it running. Solar panels, fuels cells, RTGs, you name it. You also need a decent battery reserves, for your probe to not die, once it enters the dark side of any celestial body. And don't forget about antenna! You have to keep your up-link with KSC in order to control your vessel! Do i even have to mention necessity of relay satellites for the deep-deep space missions? All of that makes unmanned missions 10 times more complex, than the manned ones, which is precisely the opposite of how it should be and how it was and is IRL. And this can be solved precisely with introduction of life-support.
Necessity of having to put oxygen tank and supply of snacks on your rocket, can be the answer on why you maybe should pick unmanned mission over the manned one, for a simple survey, that can be done autonomously and Kerbals are not even necessary for. Inability to produce snacks and oxygen for kerbals in mid-flight, while being able to produce electricity for the probe with solar panels, can be the answer on why you maybe should pick unmanned mission over the manned one, for a mission to a distant destination. Importance of sending unmanned survey missions also benefits from presence of life support, because of ability to measure the temperature/radiation levels/gravity/composition of the atmosphere, in order to use that data to understand, can Kerbals survive there and which type of life-support will they need. And have you noticed how i mentioned temperature/radiation levels/gravity/composition of the atmosphere? That's right! All the science experiments, from original KSP now suddenly have AN ACTUAL PURPOSE, other than just collecting some magical science points, that will unlock new engine for you, which once again fits very well with announced progression system through missions.
And since we are talking about progression system through missions - life-support can enhance even that. Think about how you would have to perform test-flights with experimental hardware in order to develop more advanced life-support systems. Don't tell me it won't be fun.
When you start your game you have nothing.
* After you complete your first high-altitude flight and discover, that there is very little oxygen there, you unlock a oxygen cylinder, like the ones, that divers use.
* When you complete your first sub-orbital flight and experience zero-G for the first time, you unlock tubes with food for your Kerbals, so you can actually feed them in zero-G and perform flights, that are longer than just couple hours.
And so on and so on. Possibilities are almost limitless!
And suddenly replicating X-15 flights now also have a purpose!
In conclusion i want to quote myself from my post about career mode. KSP is the game all about challenge of getting to space. If you are already enjoying original KSP, you definitely will enjoy new challenges of getting to space in the sequel, once you master them, just as you already mastered the challenges of original KSP. Don't be afraid of complexity. And remember, that this won't be boring by definition, but can become boring only if designed poorly. And just because it can be designed poorly, doesn't mean it will be. Having said all that, i am certain, that life-support will be a good addition to KSP 2, and i have faith, that Nate Simpson and all the guys from Intercept Games are capable of implementing it in the way it will be fun.
And don't tell me how Jeb Kerman, orbiting Kerbin on a Space Chair with scuba diver oxygen cylinder attached and some chocolate bars in his pocket, is not in the Kerbal Spirit.