Anime is Getting Top-Heavier every year:

The top 20 anime in my top 200 anime rankings, (ie, the top 10%), account for nearly 40% of all episode content.  Their length is four times the ranked average.  If you just watch the top 20 ranked anime in my rankings, you've already watched 40% of all the best anime out there.  And since they were in the top 20, you've also watched the most important stuff available.

If that sounds top-heavy, wait till you see what's coming out next.  While One Piece, Pretty Cure, SAO, Fairy Tail, Index/Railgun, Fate/etc, and others pour out hundreds of additional episodes, the remaining 180 ranked shows are largely done or just have a single movie planned for them.

The only shows ranked 21-200 with meaningful additional content announced are Chihayafuru, Granblue Fantasy the Animation, Princess Principal, Girls und Panzer, BanG Dream and World of Witches.

And they're only getting 6-24 additional episodes.  One Piece on its own is slated to bag 300 more episodes easy.

It's also highly possible that Dragon Ball will receive a new tv season.  Or Bakemonogatari.  Or Love Live!.  Even Bleach or Nanoha isn't out of the question.  If they do, together they could easily outpace the 21-200 crowd.

Eventually over 50% of all anime by quality and quantity will reside within just these 20 elite franchises.  Probably by 2021.  It makes all the additional ranked series feel almost pointless.

If I had to choose whether the top 20 series of anime existed or 21-200, I'd choose the top 20 hands-down.  The 21-200 crowd really is just bonus.  But I think they're good enough to still merit mention.  It's the same with my favorite composers.  I have 200 favorite composers listed, but the top 20 are already over 50% of my favorite songs.

In the end it's just a top heavy world.  The best aren't just slightly better, they're way better than everything else.  This is true of golfers, tennis players, artists and scientists.  The Lotka curve dominates all.

11 ranked franchises have contributed new content in 2019 so far, and of those, 7 are in my top 20.  7/11 is even more than 50% (64%).  That's where anime seems to be headed these days.

What with all the additional content the top 10% keep receiving, it's impossible to compete with them.  I doubt any new series will ever pierce the top 20 barrier.  Even though there's plenty to fiddle with in my rankings, it's all really an afterthought.  The titans that define the entire medium are here to stay.

There's plenty of new One Piece, Precure, Fate/etc and SAO to look forward to in 2019 and 2020, but good luck if you were expecting anything new or different.  Anime doesn't do that sort of stuff anymore.  Like the movie or video game industry, it's learned to lean on its most popular franchises and just keep making sequels.