It's really unfortunate the direction they went with Luke's story. His acting performance in TLJ is the best of this trilogy so far and may go down as one of the best in any Star Wars movie. But it still bugs me that they chose for Luke to take the cowardly Yoda route... I don't think you can blame The Last Jedi for that though since it's pretty much the entire plot of The Force Awakens. The Last Jedi has to deal with the absolutely awful plot lines TFA leaves for it.
What would be nice is if we could go back to TFA and actually plan out a decent three part story instead of starting with that absolutely unforgivable plot mess.
I'm of the opinion that TFA set up multiple decent (some great) storylines but TLJ chose the weakest and thoughtless ones:
TFA
Who are Rey's parents?
TLJ
Nobody.
TFA
What has Luke been up to?
TLJ
Sucking blue milk out of creatures with huge boobs.
TFA
Who is Snoke? Why/how is he so powerful? Is he going to be the next feared Emperor?
TLJ
Meh. He's dead now, who cares?
TFA
Wow, is Rey really force sensitive?
TLJ
Yeah, she has become a Jedi master in only a few days and can handily defeat Luke, who required years of training to get to where he was in RotJ, in hand-to-hand combat.
TFA
Kylo is an whiny, bi-polar emo prick. Think he'll become a more well-developed character throughout the next movie?
TLJ
Nah. Still a whiny, bi-polar emo prick.
TFA
So Luke has to be some awesome, Jedi master now after all these years, right? I can't wait to see him pass on his legacy to Rey and kick some major First Order ass.
TLJ
Oh really? One rushed series of "lessons" from a grumpy dude and a force-suicide coming right up!
TFA
Well, at least Chewbacca is back!
TLJ
Here's him eating a Porg while another Porg looks all sad and depressed. Children, ask your parents for Porg merchandise. Parents, buy your children Porg merchandise.
TFA
So what the heck was going on in Rey's vision? Who were those badass-looking dudes with Kylo Ren in the rain? I read something about the Knights of Ren.
TLJ
Uh... what?
TFA
Oh boy! Captain Phasma! I can't wait to see her again! I haven't been this intrigued by a side character since Boba Fett!
TLJ
Yeah, about that. She dies after a fight with Finn which lasts like a minute.
TFA
What happened between Luke and Kylo Ren? What's the whole deal there?
TLJ
Eh, he said she said.
TFA
So of course Leia is going to get a dignified death in the next one. Carrie Fisher is dead. She could barely speak during the first movie.
TLJ
Sure! She's gonna get blown into space and we're all gonna cry, but wait, here she is pulling some deus ex machina Mary Poppins crap because we're not done with her character yet for some god-forsaken reason!