Balance of the Force has been a theme throughout the saga, particularly in the prequels. I don’t know if anyone noticed but the round pool near Luke’s special rock seemed to have a balance symbol, rather similar to Yin and Yang.
I actually thought The Last Jedi gave us a really nice, naturalistic, presentation of the Force, and went a long way to retcon the mistake of Midichlorians, blood tests, and ‘all in the genes’ exclusivity that the PT advanced.
Rey isn’t a Skywalker, she isn’t a Kenobi. She’s no one. And for the audience, that makes her everyone.
Still doesn’t make sense that Rey just so happened to have grown up next to the Millennium Falcon. Then stole it and ran into Han who obviously knew Luke. Which Rey was with Finn running from the New Order and Kylo. And then Luke tells Rey that he hasn’t seen that much raw power but once before, and it was Kylo.
None of it adds up just like Han so happened to come across the Falcon after it being stolen many many years ago.