A lot of people will disagree with you.
And they'd be very obviously wrong.
A biological group advocacy ideology must,
absolutely must as a first step in everything, define everyone on the basis of whether or not they are in the group favoured by the ideology. It is obviously impossible to have a biological group advocacy ideology that doesn't do that.
So feminism is sexism on that basis.
A biological group advocacy ideology must also include the belief that only people in the group favoured by the ideology are worthy of consideration on a social and political level. That's how a biological group advocacy ideology works.
So feminism is sexism on that basis.
A biological group advocacy ideology must also promote belief in negative stereotyping of the other, those not in the favoured group. That is necessary to "justify" excluding them from consideration.
So feminism is sexism on that basis.
An ideology that was about sexual equality would not include sexism. Feminism includes any and all anti-male sexism up to and including "phasing out" maleness, i.e. a final solution to the male problem. Anti-male sexism does not in any way conflict with feminism because feminism is sexism.
All strains of feminism, including the most moderate, are absolutely and inherently sexist.
There are many things that a lot of people have thought or do think. For example, that "whites" are superior to "blacks". Or that witches are agents of Satan who curse decent people with their foul spells. Or that women can't do maths. Many, many things. If a lot of people believe something that is irrational and wrong, it's still irrational and wrong.
EDIT: Including a link to feminist propaganda written specifically to divert attention away from the truth with baseless denials and more blaming of the target group is not evidence of anything apart from deceit, which is of course to be expected from advocates of biological group advocacy ideologies. Go out tonight and find some guy living rough on the streets and tell him how priviliged and powerful he is compared with, for example, Angela Merkel. Maybe you'd even be deluded enough to believe it.