Literally the whole point of Luke showing up and making a scene is inspiring hope across the galaxy.
“The Rebellion is reborn today.”
The Resistance won’t be able to fit on the Falcon for long. This is made pretty clear in the film.
Yeah, but that all depends how the FO will rule the galaxy. It’s not two major organisations backed by various systems like in the OT. In ANH many systems were rebellung against the Empire, because it was oppressing the galaxy. Now it’s hundreds of thousands of troops versus fifty people. If the FO are smart, there won’t be a Resistance ever.
Luke didn’t just inspire little kids with brooms. He inspired everyone who sympathizes with the Resistance’s plight, including, as is implied, their allies in the Outer Rim.