You can fly a literal Godzilla shaped ship. I mean, what more could you POSSIBLY need?
Joking aside, it's no surprise people are excited. Starfield is looking as if No Man's Sky, Elite Dangerous and Star Citizen had a child. And anyone that has even a passing interest in science fiction/space exploration games (that includes me, obviously) has always dreamed of something like what they propose. A ton of systems to visit and stories to accompany you on your journey. We will have to see if it's as good as it looks, but they've definitely shown enough (imo) to pick people's attention.
I've always had a huge interest in this sort of game and i have to say, i'm very skeptical of what i saw. I wouldn't compare this to SC and ED, as those have more solid systems like working living economy and planetary physics, not to mention MMO-like features. This has none of that, it really is a lot like NMS with Fallout sprinkled on top, and thats more or less what had me worried.
NMS has a lot of the systems showcased and they all have the same problem, no synergy between them and too shallow to be worth engaging with by themselves. The way they've showcased Starfield range of activities gave me the same impression. Thousands of settlements to invade and shoot up for you to eventually realize none of the loot is worth the trouble and that they are all more or less the same. All these ship customizations, barely any effect on how you play the game. Lots of base building options but almost no use for the stuff you obtain through them. Tons of systems that seem designed with some vague goal in mind to make you "bigger", "richer", "more powerful", etc; but why you want to be any of those? Will any of that help you towards some bigger goal, like how getting stronger in a rpg lets you fight stronger enemies and explore areas with higher level? Its all optional so they kind feel like they were just attached to the game. In games like x4 or Factorio, where you also "grow" indefinitely, theres usually always some bigger carrot to chase, not to mention the systems are designed in a way to be engaging and your actions have clear, often visible, consequences in the world around you, which makes them satisfying to play. I dont see that here in Starfield.