This is the full definition of radical feminism given by Wikipedia:

Radical feminists assert that global society functions as a patriarchy in which the class of men are the oppressors of the class of women. They propose that the oppression of women is the most fundamental form of oppression, one that has existed since the inception of humanity.

Does any of that sound familiar?

Radical feminism has its roots in the 1960s during the civil rights movement where it compared the position of women in society to the position of African Americans. Something that many African Americans, including African American women, objected to at the time.

The word patriarchy started being used in that context during the early 1970s where it quickly became associated with the movement. Radical feminism is the only type of feminism with it's own distinct ideology and vocabulary. Other forms of feminism largely borrow from existing political theories. They just focus on women (or gender equality) within those frameworks more heavily.

For example, the definition of liberal feminism, also sometimes called "mainstream feminism", is,

Gender equality through political and legal reform within the framework of liberal democracy.

This is the definition that feminists like to cite when they fall back on their "dictionary argument". The only problem is that patriarchy theory is not a part of this definition, or of liberal feminism more broadly. In fact radical feminists often criticize liberal feminism for rejecting their views about the patriarchy.

Patriarchy theory benefits radical feminism by abstracting away the explicit comparison to racial oppression that it is based on. During the 1980s, after the civil rights movement, this interpretation helped give it wider acceptance. This was especially true in academia where it became the basis for gender studies.

Radical feminism doesn't just attempt to appropriate the struggles of African Americans onto women. It also tries to adopt the rhetoric and beliefs of black supremacy and frame the narrative in an "us vs them" mentality. Something that was rejected by black civil rights activists. And makes radical feminism more of a women's supremacy movement than a movement for true equality.

A further development in radical feminism was intersectional feminism, which tried to give room for other forms of oppression besides oppression against women.

Many intersectionalists try to say that intersectionalism is a response to radical feminism, as if that somehow makes it "different" or "better" than radical feminism. But the reality is that intersectional feminism is still founded on the idea that women are oppressed through a patriarchal system enforced primarily by men.

This type of feminism has become popular in BLM, LGBT, and SJW spaces, but has recently started facing backlash from inside some of these groups as well. The intersectionalist approach emphasizes oppression and an "us vs them" mentality inside of these communities. And it is often viewed as a radical, unhelpful approach in this context as well.

So have you ever met someone trying to distance themselves from radical feminism, but then also claim that there is a patriarchy, or that women are an oppressed group of people?

Just because this belief is more common today does not make it any less radical than it was in the 1960s.

Men do not oppress women. And women's issues do not come anywhere close to the struggles of African Americans. Including, and especially, in history.

Sources:

https://en.wikipedia.org/wiki/Radical_feminism

https://en.wikipedia.org/wiki/Liberal_feminism

https://plato.stanford.edu/entries/feminism-political/

https://www.humanrightscareers.com/issues/types-of-feminism-the-four-waves/