Starfield is an incredibly mediocre game. Had it not come from Bethesda, a company with a built-in fanbase who adore the RPG elements they are so good at, this would be generally reviewed much more poorly than it currently is. The shooting is bad, the UI is awful as many things are burried in an obtuse menu system, and while there's certainly a lot of space to explore it must be noted that most of it is barren and lifeless; its like touting that you have a huge house but after buying it you could only afford to decorate the living room. What's the point of all these planets, and outer space, if there isn't much to do in most of it? While they certainly nail the RPG elements, the game they build around that stuff is just OK.
The biggest sin however is the near complete lack of ship-space exploration. You can fly around in space in your ship but you never feel like you're going anywhere. They went for "realism" in that every planet is astronomically far away from the next. So much so that it's borderline impossible to simply fly from one to another. That's realistic alright but is it fun? Even worse, when you are in low orbit near one you still cant just fly down to it's surface. You need to go through menus to land (and take off) and watch a cutscene. It's incredibly shallow.
If you're a fan of Bethesda games you probably already know what you're getting and have decided to be fine with that. If you're not, or want more out of your game than just roleplaying, pass on this one until you can get it at a discount.