I don’t know much about the WI, but I am in favour of anything which encourages women to meet other women, and to do things of their own and broaden their horizons. I imagine it must have been a godsend for many women. For that alone it counts as feminist in my book, jam or no jam!
It’s hard to identify a single thing that would make society less patriarchal. Particularly anything remotely possible. If I had a magic wand, for example, I would abolish all porn.
There are things that men could do that would improve things overnight. I think for women it’s a case of speaking out clearly as often as possible and stopping putting up with crap, both on a macro and a micro level. Every time a woman says to a man “I will not wipe your piss from the loo seat or pick your dirty pants off the floor”, she is making another microscopic crack in the patriarchy. Particularly if children see her do it. And every time a woman challenges her company about why she is the only woman on a 6 person panel- that’s another crack.