Frankly, I don’t care about “The Star Wars Universe”. Star Wars had inconsistencies between movies since Empire. What I do care about is a watching a good movie. And in the context of TFA, the quick gain in Force powers serves to advance the plot, instead of wasting time with some sort of training montage.
The same applies to Broom Boy. At my first viewing, I even missed that he used the Force to get the broom. Having him reach out and try several times would have put much more amphasis on it. The point of that last scene is to show that the Force is something natural. So yes, maybe the ways of the Force changed for the ST, but I don’t mind how they changed.
Well I do care about the change, because gaining Force powers and facing moral choices was indelibly linked in the OT, and the saga as a whole before the Disney acquisition. In fact it was the underlying theme of what becoming Jedi represented: making the right choices, dealing with temptation, learning that with great power comes great responsibility. So, what you describe as changes to advance the plot in order not to waste time, I decribe as throwing out the baby with the bathwater. Consequently, for me Luke’s statement in TLJ, that he will not be the last Jedi, sounds extremely hollow, because becoming a Jedi used to mean a lot more than instantly gaining a bunch of super powers, and being a legend in the eyes of the galaxy.