It's important to start off here by defining "radical feminist". It's very common in misogynist places like TheRedPill for people to use "radical feminism" to mean "feminism that I think goes too far in describing women's oppression or blaming men as a class for it," and in a lot of ways that has seeped out into the rest of the internet. The idea that western society has long been patriarchal, and that sexism consists of the social and legal oppression of women, is common to feminism as a whole. The main divergence between mainstream feminism and radical feminism is that mainstream feminism supports change from "within the system", while radical feminism posits that the entire system needs to be dismantled - much like the distinction between economic leftism and American liberalism.

The reason I'm explaining this is that you're going to have to go very, very far to find a feminist who doesn't think that women have historically been cut off from power by being denied a presence in "the government, military, universities, science, finance, etc." by men (and that radical feminists wouldn't believe that this was done through "sexual domination" since that doesn't make sense). Radical feminists might make a problematic blanket assertion that male supremacy dates back to the beginning of humanity or to the turn from hunting and gathering to settled agriculture in different societies, but it is patently obvious that women have been excluded from power and influence historically in many societies around the globe.

To use one example I'm most familiar with, let's look at eighteenth and early nineteenth century England. Women could not vote for members of Parliament even if they met the requirements placed on men to own a certain amount of property, and they of course couldn't stand for election themselves; women were also barred from inheriting aristocratic titles from their fathers as a matter of course, so they could not sit in the House of Lords, and even in the rare cases when women held titles in their own right, they didn't take up a seat either - so that is restriction from the entire legislature, the functional government. They would only inherit the crown if they had no brothers, so they were in general unlikely to hold that level of largely ceremonial power, either. (Victoria would come to the throne in 1837 through a series of unlikely accidents and coincidences.) Locally, women could not serve as magistrates or mayors or aldermen. And even on a personal level, the legal principle of coverture meant that a married woman's property and children were her husband's to dispose of; if she divorced him - an option only available to a very few at the time - he would have custody of their children and she would be socially ruined.

Women were barred from the military, from universities and medical schools, from seminaries - which prevented them entirely from having professional careers. Women's education as a whole was scattershot, including fewer and fewer academic topics down the social scale, with working-class girls mainly taught to sew, cook, and clean, skills which could help keep them alive, but certainly not advance in the world. Women did not learn trades (with the exceptions of millinery and dressmaking) except as the daughters or wives of artisans, and were often prohibited from practicing said trades on their own as a single woman or widow. Male artisans specifically opposed women entering e.g. weaving because women were paid less than men for the same work, and therefore they saw it as an encroachment on their rights and livelihoods.

For the vast majority of women, their options for life were a) to get married to a man (who could subjugate and oppress you very easily if he didn't think about specifically not doing it) and revolve your life around his career and preferences until he died, or b) to accept a precarious situation, potentially destitution. Even an elite woman who didn't marry would be socially required to live with her parents until they died, and then (unless she inherited a lot of money) to be generally dependent on other relatives afterward for housing. Middle-class spinsters would be entirely dependent on relatives, and working-class ones would expect to be in domestic service until they died. And more than that, society saw them as ridiculous failures, constantly portraying them as ugly, interfering, too unromantic or overly romantic, prying, stupid, etc. etc. etc. in fiction, cartoons, and plays.

So I mean, what is the alternative argument to the idea that society at the time was patriarchal and excluded women from power? That it's simply a coincidence that society was constructed to make women unable to support themselves and keep them under the control of men as much as possible?

But then we have to look closer, and to be entirely fair to your question, this is where we do typically lose the radical feminists (as well as the misogynists). Because there's a lot of fascinating nuance about how women actually lived and worked in this society that was so fully stacked against them. This could range from individual women being celebrated as exceptions, "surpassing their sex" at some field typically considered male, to simply wielding a high level of influence. Women could not stand to be MPs or vote for them, for instance, but an active (if likely widowed) female landowner could make her preference plain and expect to have the men in her district largely vote her way. I discuss these sorts of situations in a number of my previous answers.