I don't think so, I believe Biden is the real reason Harris lost. She had too much ground to make up for Biden's stubbornness to realize he was a weak candidate. Trump's entire strategy was based on how weak Biden was and the party turning against him in the 11th hour only reinforced Trump's claims. Kamala was doomed from the start, I believe she could have won if she had taken the lead from the start of the race. She wouldn't have been my first or even my second but I still think she could have won if Trump didn't have a head start and Dems taking so long to pull their heads out of their asses.

if she instead had been a white male

I feel like the most obvious counterfactual here would be if Biden had kept his faculties and run for a second term - an establishment politician running for business as usual. And I don't think he would have won. His presidency had left people disillusioned with him and seeking something new, and more of the same - regardless of the wrapper - was going to lose. Not to say that a woman of color doesn't face more barriers than a white man - but I don't think those barriers were the determining factor in Harris' loss.

But if she instead had been a white male, it's very possible trump would have lost.

You mean a white male like Biden who was in the race before her but dropped out because he was doing so badly?

I always find this argument weird because the people making it typically argue that "America is too sexist to elect a woman" but then go on to infantalize women by claiming that they don't win because they're women. It's never about their campaign, their choices, or their performance like you would talk about if a man had lost. They're always boiled down to one thing and that thing is a "helpless woman."