Starfield felt much bigger for me when I didn’t use fast travel. I used to play Elite extensively so needing to walk back to my ship and take off and then needing to plot a course to my destination makes it feel larger. I agree with you on the you’ve felt that you’re only 10 hours in and then when you checked your playtime you’re already 30 hours in.
In my case I just played a couple of faction quests and I’m already 60 hours in. Coming from Armored Core 6 I just basically spent most of my time building ships.