Think about the Rebel Alliance. Out of a galaxy of a quadrillion or so beings, they numbered what? A few million at the absolute high end?
And that number is including informers and the like. In terms of people engaged in active combat operations they were substantially less.
Bail, Leia, Mon Mothma, Ackbar, etc. were so utterly removed from the common citizen of the galaxy that about the most you can say they had in common is that both groups ate, shit, and breathed air.
The Empire was evil, but for the average person on the street? Nothing at all really changed.
For those active in the galaxy, tons changed. But for the average person on the street?
Take Rogue Squadron. These were literally the absolute best pilots that the Rebellion had. If they weren't then they would never have been on the same base as the leadership of the entire Rebellion and acting under their direct command like they were. So of course they are going to be able to run rings around the Imperials.
Basically, no one we see is representative of the galactic norm.
And yet a lot of the time the community treats them like they are. Han is, even before he meets Obi-Wan and Luke, considered one of the best smugglers in the galaxy. His rolodex is a whose who of the galaxies criminal element and organizations. He was personally smuggling spice for Jabba by the ship load. Jabba the Hutt, one of the five or so most powerful crime lords in the galaxy, was *personally* hiring Han for jobs.
So yes, Han can show up on a planet and be meeting face to face with the biggest criminals on the planet in a few hours or days. Not just because he knows who to talk to but because everyone who is anyone in the underworld knows who he is and his skills are both useful and proven. The mere fact that
Han Solo came to that person for something is a massive reputation boost to them. The favors game? Well Han can provide an introduction to basically anyone who is anyone in the underworld.
Does that mean the galaxy wouldn't have cared about Alderaan if Bail wasn't among the dead? Also could it be argue that the setting of Star Wars is too big? Like instead of taking place in an entire galaxy it maybe should have only taken place in a couple of solar systems? (if that many?)
Of course not. Alderaan was a founding member of the Republic and one of the leading Core Worlds. It was also one of the wealthiest worlds, per capita, in the entire galaxy. Poor on Alderaan was still staggeringly wealthy compared to the galactic average.
And no, the issue isn't that Star Wars is too big. It's simply that the scale is often overlooked or not considered when people discuss Star Wars.
Creators of SW media are often guilty of this as well.
I mean think about an ISD Captain. Everyone who got that position, all twenty five thousand of them, is there for a reason. If they are connected, those connections are too literally the highest of levels in the entire galaxy. If they are there on merit then it is because they distinguished themselves on that scale.
Vader killing Imperial officers who displease him? Why should anyone care, there is literally a thousand people eager to step into the dead man's shoes.