Has anyone felt this way?

The more I've read, the more I see the same themes and plot-lines over and over again to the point that many stories become way too predictable and less emotional. I also find myself becoming more and more critical of what I read because I see so much monotony. I look for something unique and invigorating with good writing because the more I experience, the higher my standards become.

Maybe you're going through the same thing? It's not necessary that they aren't enjoyable anymore, but you simply expect more from what you read.

Yeah I am still able to enjoy it, but I definitely grew out the zeal I used for have for it as a young teenager.
More so, I guess I just grew out of it. Then again it might have something to do with the quality of the shows too. Now a days there's a lot of fan service and the genre I used to love is less aired? I still can enjoy it like I said, and I'm capable of talking about it, but I guess I just found new hobbies.

Yes so true I have been like that for a while now I even say why am even watching anime or manga but them went I started watching some anime or reading something interesting it gave me that emotional again like the anime 91 days ╥﹏╥ but is going to pass and you will be interesting in manga and anime in not to long ヾ(☆▽☆)

I know this feeling. Manga and anime got more and more boring over the time for me. Especially BL because I have the feeling I've read everything there is and it's all the same in the end. I don't buy many manga like before. Only one or two every other month and not the ten o twenty *every* month. (I did save so much money recently xD)

And anime recently looks nice but the plot is meh or not my kind of thing (like thriller, drama, slice of life)
That's why I liked for example Yuri!!! on Ice that much. It surprised me in so many ways; with it's plot and characters and animation and all. It was something different than the usual anime with their fanservice.

Well it could be multiple reason. Like your taste are changing etc.
But another reason is that your reading too much.
You gotta switch it up in a while.
For example you could really love this band and the music they make so you listen to them everyday.
But one day you get tired of them cause you overdid it.
I mean I myself I'll watch or read anything from any country in any medium as long as it's good. Variety is key.

The last thing I've watched was YOI and before that, Death Parade in it's original run. I've watched so few unlike before when I enjoy a lot of Anime. Now, I mainly rewatch animes of my childhood for nostalgia and stuff. It's just more of a cycle. I've felt this way towards TV series too. The brain just can't take too much of something. Let it miss watching animeand enjoy what you can right now.

I agree with the other peeps. Take a break.
Read something else. Maybe read a actual book or watch a ton of netflix for a couple of days/weeks/months.
And when you come back, if you come back, you can get a fresh start. A lot of your ongoings should have updated, and there will be new and possibly good manga to read.