Characters come and go. Young heroes age and become old. New generations take over. Bilbo might have thought about going on that quest, but it fell to young Frodo.
Having old characters retire and become wise mentors to a new crop of adventurers is a way to provide a depth and continuity to a campaign. Sure, you can try recruiting them to help, but at some point they're going to be too old to be much use in a fight. But have them appear in the background, back at home, in briefings. Their presence should be felt.
Commentary by memnarch (who has not seen the movie)
Well, that was a good try, Rey. I guess Luke likes his rainy planet and fish people neighbors a little too much though. You should still try and help him up; Luke's no spring porg anymore. And maybe ask for clarification on if you've got everything you need to defeat Kylo as well.
Jedi records being useful? I can't really see how. Movie-Rey probably wants them for instructions on training, or maybe sentimental value of some kind, but that's more of an extreme long-term planning sort of thing rather than a fight prep thing. Comic-Rey doesn't have either of those reasons. And even considering they're full of midi-chlorians since they're paper, we've yet to see anything that suggests the midi-chlorians can be extracted from the paper for any sort of use.
Transcript
Rey: Come with me. Help defeat Kylo and Snoke. You want your sword back? {offers the sword to Luke}
Luke: No.
Luke: It’s time to pass the torch to a new generation. I’ll just be in the way.
Luke: You have everything you need to deal with Snoke. Never forget, those swords are just as dangerous to the wielder as the defender.
Luke: Do you know where the Resistance is?
Rey: Mum... I mean, Leia sent me a message. They’re heading to Crait.
Luke: Mmm. I know the old Rebel base there. It’s no Helm’s Deep.
Rey: Mind if I take the Jedi records from the tree?
Luke: What do you want them for?
Rey: In case my brilliant plan doesn’t work, we have a much more ridiculous long-shot back-up plan.
Luke: Sure, take them. Though in my experience, you’ll be better off trying the other plan first.