Tank Meta
It seems that no matter what stage of the meta League is in, it always seemingly starts to shift toward the tank meta again and again, after every big change in meta (like adc meta with new adc changes pre-season and rageblade meta (with devourer junglers as well) where hybrid damage and devourer junglers are making use of the splash damage it provides with its hybrid stats), it slowly starts to shift back to the tank meta.
Anyone able to provide some insight on why this seems like the case? Are strong tanks what constantly dominate the meta and change shift it back?
or 
that is able to not only able to break through enemy lines and easily cc and disrupt any team-fight, but also is extremely difficult to kill).
is a prime example of such a bruiser). Though I feel like the role of such bruisers shift the prime goal of a tank to help the team through defensive means, but I cannot say that bruisers aren't able provide just as much assistance as a tank, as their goal is disrupting the enemy team, allowing the damage dealers to be able to execute the enemy damage much easier.