Like Apollo which preceded it in the 60s, this is a developmental programme in which each mission uses proven tech, and adds on new developments. Apollo 1 through 7 developed and proved the basic space-worthiness of the vehicles, 8 explored the tech to reach the moon, 9 the ability to rendezvous in Earth orbit, 10 took that rendezvous-technology to lunar orbit and 11 actually landed. Artemis does all that in 3 planned missions, presumably because greater reliance can be placed on developments due to the ability to test computer modelling, and the shear experience of being in space for 6 decades.
What I find particularly interesting is that Apollo was laid out in the early 60s and every schoolboy (it was the 60s; it was a boy-thing) knew the names of the modules, length of the journey, how the modules interacted and so forth well before any of the tech actually got close to the moon. The difference with Artemis is that NASA was quite open early on that how they will get from lunar orbit to lunar landing has not yet been developed; they are still just assuming that something will be facilitated by emerging technology. That's the difference between fact and fiction; if they were just making this stuff up, they wouldn't have to wait another 2 or 3 years to actually work out how to build something.