I'll try to be as concise as possible.
I prefer summarized lore, yes, 5 sentences are more than enough to understand who this character is.
Tristana: She's a military yordle. Cool!! Do I care if she wants Teemo's D? nope.
Is it cool to know these small tidbits of information? definitely! but honestly I would hate, HATE! to read a full 5 pages essay on Trist x Teemo.
The format in which lore is given out must be flexible, walls of text are cool for some people, for others it's a pain the ass, the summarized version are enough to light people's fire and make us look into it weather it's inside the client or outside I don't care.
Same thing with the JoJ, SOMETIMES, the JoJ had cool and interesting information about champions but more often than not, it was superfluous information, like: Poppy used money ........... it was infuriating because I felt like I lost my time reading something akin to Paris Hilton's life, one time is funny but the JoJ was filled with things like this and it's understandable! compelling and interesting stories don't happen weekly, it's crazy to think they do, specially with the amount of work narrative does inside Riot.
What I think would be awesome would be a LoL comic of sorts, each lore for each champion having their own webcomic, though you can imagine how much work this would entail, if only writing it is crazy time consuming, imagine drawing it :x it'd be cool nevertheless.
TL;DR: Summarized lore is cool and concise, think of a TL;DR format for lore and this is what you end up with