The left has TONS for men. You think men thrive under the patriarchy? Not being able to express emotions, not being able to express fraternal love, not being able to pursue "womanly" or"gay" passions. Men have rarely been more alone and less happy than they are now and left wing ideology can free them.
The left just doesn't reach out like the right does. We could do a much better job.
The online left also doesn't do a great job calling out sexism and other behaviours that uphold the patriarchy when it victimizes men. That's pretty shameful and it's hard for men to feel safe online in leftist spaces. In person I've never had a problem and people have been wonderful. But it's a barrier to overcome that isn't there on the right. The right says "you're amazing because you're a man, join us and regain your rightful amazing place that your deserve". That's a hard message when one side says you're amazing as you are and the other, the side that prides itself of being open and accepting, is proud to tell you you're worse than a bear and you shouldn't feel hurt by that because it's what you deserve.