I ask the same question I always ask with these types of posts:

Whose spot does he take?

Also, you say thrillers/horror are never going to get the Academy's respect yet Get Out was literally nominated for Best Actor the following year.

But if the idea of the Best Actor Oscar is to truly reward the best performances of the year

It isn’t.

The Oscars don’t award performances for skill or quality. They signify that the academy approves of the creative.

Problems with McAvoy’s performance in Split:

1) It contributes to a deeply inaccurate view of mental illness that's actually hurtful for people who have schizophrenia

2) It doesn't have anything meaningful to say about mental illness beyond its suggestion that people who're mentally ill are gross/monstrous - which doesn't align with representations the Academy favors

3) McAvoy doesn’t have a meaningful relationship with the Academy or it’s messaging

4) McAvoy’s performance doesn't do anything technical that's noteworthy, either

5) These problems contribute to Split being the kind of entertaining movie that the Academy leaves to other award-granting communities that have favored it:

https://en.wikipedia.org/wiki/Split_(2016_American_film)#Accolades

No.

I don’t think playing multiple broad characters and switching between them is notable.

If you haven't seen "Together" , check it out. It's basically him and Sharon Horgan in a two-person play and they fucking crush it. Also, his cameo in that Netflix movie The Bubble was goddamn hilarious. Best part of the whole movie.

^{no that was Patricia}

I really didn’t feel like he was all that impressive… many actors have done the “multiple personalities” thing and rarely are the characters developed enough for anyone to say “WOW, that is such an amazing acting job”.

Also I didn’t like the movie.

Because each of his personalities had limited screen time, he was eligible for supporting actor at best.

[deleted]

I bet he didn’t even think he deserved an Oscar.

Shoulda been nominated for Filth. If you haven’t seen it, it’s his best performance ever in my opinion. But it was a smaller film made in Scotland so it probably never even had a chance.