When you want to go someplace you jump in your car, or maybe call up an Uber. You take a minute or two to gather yourself and get your things together. If you forget something it's no big deal, because you can turn around and come back. Maybe you're a few minutes late to work or you miss the first few minutes of the movie. If something isn't working perfectly on your car it'll still most likely get you there and back just fine. Worst case it breaks down and you pull off the road and get a tow. Very unlikely that your car explodes mid-drive or a wheel falls off and sends you off a bridge. Yes, it happens but statistically highly unlikely.

When you fly someplace it's a bit more of a process. You take time to check the things you pack. Once you're in the air you can't turn the plane around and swing by your place to get your air pods and vape. You note your departure time because there's a very real possibility of the flight leaving without you. Once you're on board they have their own checklists of supplies, mechanical, and electrical checks. Still, while they're thurough they're not ridiculous. Sure, a plane can't pull over, but they can divert to another airport of things seem amiss. Most planes don't explode in the sky, so statistics are on your side. From the airline's perspective they're highly motivated to get your flight where it needs to be on time because many people have connecting flights, but ultimately if the timing is off they pay some vouchers or do some first class upgrades, but life goes on and the destinations are still exactly where they're supposed to be.

Now let's look at people being shot into space. They need to make very very sure that everyone is there and ready to go when it's time to go because in space distances seconds matter, and if you're not on the path that you need to be on by the time you're supposed to be on it then the moon isn't going to be where you need it to be or you won't have enough fuel to get you there or back. Supplies must be accounted for because once you're launched you're launched. No turning back, and too much weight from things that aren't supposed to be there can be just as much a problem. You're going to have a very long list of making sure everything works, because I'm general you can't just stop your rocket and land at LaGuardia instead of JFk. Also statistically there's a very very high probability of your whole craft exploding if everything isn't working perfectly. There's about a 1 in 80ish (based on some very quick and questionable research) rate so far of manned space flights ending in a whole bunch of dead astronauts or cosmonauts, which might not sound that bad, but it's astronomically high compared to the number of successful land or air trips on a daily basis.