When the 1st Little Big Planet game first came out, everyone thought it to be the "true competitor" to the Mario franchise. The 1st game  sold nearly 6 million copies worldwide. Over the years the games has gotten SO MUCH better, while the sales got so much not better. I played LBP3 and it's a masterpiece! My favorite LBP game yet! 

Little Big Planet Vita > New Super Mario bros. 2

Little Big Planet 2 >  New Super Mario Bros  U 

NSMBWii > Little BIg Planet

Little Big Planet PSP > NSMBDS

Super Mario Maker > LBP3

I do love both series but Little Big Planet is slightly better for me. How can this beautiful 2D series die out? Is it because of Mario? Popular FPS games?. It's a shame that Nathan Drake took the title away from Sackboy as the Mascot of the company.    

Because Leoj and DJmiester

Wait for 3D LittleBigPlanet.

As in 3D instead of side-scrolling, I mean, no 3D glasses bullshit.

Because it didn't change that much. It was a level creator at heart, nothing more.

I love LBP, it's my favorite series, but LBP3 is definitely not a masterpiece. It's glitchy, lags a lot during online, freezes when just simply looking for community levels, etc. The fact that I bought the game basically a year after launch and that these problems are still in it and haven't been completely fixed yet is horrible on Sumo Digital's part.  I still love it and think it's a fantastic game but Sumo Digital really fucked up on some stuff especially online stuff which, in a game where online sharing and community is a majority of the game, is a huge problem. The game is still absolutely great like all the other LBP games but it needs a lot of fixing to get back to their standards imo but Sumo Digital still did a good job for their first LBP game. It just needs a bit more fixing. 

Also the series isn't dead. LBP3 might not have sold as well as the other LBP games so far but that doesn't mean it sold bad in general. LBP games generally have really long legs anyway. LBP3 will probably sell close to the other LBP games over time. 

The audience was not there on the new consoles/handhelds. Mario was able to survive because Nintendo was able to build that franchise from YEARSSSSSSSS ago.

I like LBP, so much that I even tried to plat the first one xD I think the series didn't evolve enough, I know that's what made me lose interest anyways.

too much to fast, notreally much difference between the games. LBP3 should have gone 3d platform that would have invigorated it especially with the PS4 doing so well.

I've seen Tearaway and there was no Sackboy or level-creator so :P

Is there some core 3D platforming going on for Dreams? As in having single-player plat? Honest question.

Pretty much this. Maybe if they did a better marketing for LBP3 it would've succeed a bit more, plus the fact it also came to PS3 and holded the PS4 version could've influenced.  I'd also like to note that LBP3 was a buggy mess at launch but was patched much, much later. These little things do matter.