And let’s not forget that the Jedi Academy is a school. They come as children and the Jedi have to teach them literally everything. Reading, writing, math, science, history, as well as the Jedi powers, Jedi code, law, diplomacy, lightsaber combat, hand to hand combat, leadership, tactics, technology, piloting, driving, etc. Being a Jedi in the Old Republic is so much more than lifting rocks. But when you start ticking things off, a lot of that can be learned elsewhere. In the PT we never see Jedi powers taught. We see some younglings practicing with a lightsaber (an indication of how elementary what Luke is learning in ANH is) and we see two padawan accompanying their masters on missions. By that stage they have learned all their classroom lessions and are doing their apprenticeship in the field. In the OT we see one lesson with Obi-wan for deflecting blaster bolts and then lessons with Yoda levitating rocks (perfecting what Luke had done earlier in the Wampa cave without any instruction). That is all we know. Anything else is guess work. Rey went to Luke expecting training to manage and perfect her use of what she had learned from Kylo Ren, but Luke only gave her the basics. So she took the texts and left. Oh, from kind of a throw away line, evidently Ben Solo was the same type of natural she is.
So I really don’t understand this insistance that this violates the previous 6 films. I also don’t understand how it is Rian Johnson’s fault when the character was created this by JJ Abrams. Rian gave her a nice arc about facing her parentage and being rejected by Luke and accepted by Kylo, but she can’t join Kylo. He did not give her a bunch of new force powers on top of what she already had.