I mean unless there's a wildly different implementation Starfield isn't exactly something unheard of or brand new. Mass effect in the 2000s basically did the same thing of traveling to specific planets within a RPG setting. No man's sky has more space exploration allowing travel to pretty much every planet.
As for being amazing because it's coming in 3 months. Lol. This writers an idiot. Games are developed years in advance and of course show them off them near release. TOTK had gameplay previews about a month before release and that was in development for 6 years.
none of the mechanics are unheard of, having all of them in a single game is whats impressive. Entire planets that are proc gen but all look incredible and have lighting/graphical features we've only seen in games like RDR2/HFW like long distant mist/fog, except they also have handmade flora/fauna and have been designed to be generated a certain way with specific biomes.
the ability to land anywhere on a planet and explore, but with handmade content being placed dyanamically along your path so youre not just wandering through empty wilderness for hours.
The ability to build a completely custom ship, with an interior, hire a crew to run it, and fly it around space while trading, bounty hunting, and even boarding ships which you can then rob.
The ability to build colonies almost anywhere and staff it with crew or followers.
Multiple factions and large handmade cities each with a completely different theme based on popular sci-fi tropes like Militaristic federation, Space western, and Cyberpunk. All with handmade quests, NPCs, locations etc.
and on top of all of this an entire BGS RPG with decent looking combat, quests, RPG systems, all the interactive systems that make their games unique, and more handmade content than any of their previous games.
So yeah, if you look at the individual parts its all been 'done' but never all in one game and often not to the quality seen here. Like the proc gen terrain in this game blows any game using proc gen out of the water. Hell it blows most games with handmade environments out of the water.