TL;DR is evil spell degrading people to illiteracy...

Some mean it means "Too Long, Don't Read" - an imperative to other readers seeing this...?
Or it means "Too Long, Didn't Read" - a not much correct English sentence...

Actually, it should say "it's Too Long, I Didn't Read it". Now consider, where all those "i" and "I" vanished ? The side "i" were dropped altogether, and the middle "I" was degraded to lower-case, bent and pushed below the base-line as ";" as a very inferior and perverted "I" - and that is precisely what this does with your Personality...

It may also be in Hebrew, tal dor תל דר, which means "lofty generation". This is also, what it does of people, they think they are smart, if they refrain from reading and just watch videos and films instead...

Sometimes stand before glass window of a book store, if there is still some in your town, imagine the amount of letters in each book, and remember there were times, when people were indulging in reading all those lengthy pages full of letters without pictures, without bold and underlined sentences...
And it was improving their fantasy, and then improving their creativity skills, unlike films, which provide ready-made visions, which do not improve one's creativity but suppress it, and which are often pushing perverted and distorted views of reality, wrong patterns, and since people are more and more spiritually deaf, the film emotions need to be ever more amplified, making people ever more spiritually deaf...

Because within "Book World", the better author was winning and was read more, but in "Film World", the more rich (((Oligarchs))) win and push their Opinions Forming the Population, and Amateurs have got almost no chance without expensive effects and star cast...

Which is why (((they))) strive to push you away from reading and thinking, and instead they are enslaving you in front of their Screens, because normal healthy emotions became dull compared with film emotions...

During reading of a Book, you have plenty of time to Think about it, and you are Free to stop or pause at any time, but during watching the Film, you are just Hypnotized following their prescribed way with no much time for own contemplation...
(If you're still watching "fiction" films, which I probably haven't last few years, but when did it happen last time, that you voluntarily paused the film to spend few minutes or hours thinking about that and imagining something...?)

πα½