Men can’t be feminists due to its inherent nature as advocacy for women’s rights for the sake of equality.
I tend to agree with many feminist ideals, that being said - I don’t call myself a feminist. feminism, at its core, is about fighting for women’s rights to achieve equality, and is about abolishing patriarchy first and foremost.
This isn’t to say that feminism = hurting men, or fighting patriarchy = oppressing men, to be clear - what I am saying is that women’s rights is a huge, unavoidable angle of feminism and I think this is something that can’t be separated.
Now, because of this - I think if you’re a man who fully supports women’s rights and getting rid of patriarchy as a cultural standpoint, then you do agree with a lot of feminist ideals - but I think to call yourself a feminist means you’re also inviting yourself to a space that isn’t inherently yours. To me, a man calling himself a feminist is akin to a straight person calling themselves a part of the lgbt community, a white person fully inserting themselves in a movement intended for the advocacy for a minority group or a rich person insisting they’re a part of the working class.
I think that as a man, you can fully be an ally and an advocate for feminism without really being one. In other words, if you think being called a feminist is imperative to your belief system. Ask yourself why.