Shit... I thought I answered this but must not have finished composing it. I've been blacking right out at my computer at the end of the night/morning, and waking up so stunned I have trouble replying to posts and then even shutting down my computer (root password fumble, shutdown -h fumble lol). It's a vicious circle of not getting enough sleep in bed (both cause and effect).
What I (apparently, almost) said was that unless you're going to spend a lot of time at it to make your own interesting game out of this sandbox, it's probably not worth 100 bucks to you. I'd envision you liking it, playing a bit of the campaign and then on with the next. I can see why a lot of people might say it's boring. So unless it's something you're going to play for the rest of your life (there are something like 1000 star systems) wait for a sale
I don't think you can fly into the atmosphere of a gas giant. You don't actually approach planets yourself, you bring them up on the planetary map and click to choose a landing site (whether a facility is marked or not). Clicking on a gas giant simply tells you that you can't land there (I checked, just to make sure it wasn't stupid lol). There are usually several moons and some might have marked facilities. That shit is random in random systems I'd think (not sure about mission systems).
No Man's Sky was a silly, cartoony simulation of a universe (in the game I mean). Created by the "Atlas". That's why there were no gas giants and you could land on every planet.
You don't fly your ship in the atmosphere of a planet in Starfield, you only land and take off. So if you want to get closer to something, you'd get in your ship, take off, bring up the map and click for a new landing site etc.
While actually flying your ship in space, even with boost engaged, it's not fast enough to traverse any great distance in a solar system. That's more for space combat and docking approaches on space stations.
Anyway, you haven't finished Assassin's Creed Odyssey. Wonders await. Seriously, you should go back to that one.
There's still Far Cry 6 too that you haven't finished. (and I need to get back to that myself, I've been enjoying that... very nice pace etc. and I haven't gotten angry at it yet)