I have seen the sexism first hand and it is pernicious. I regularly interact with one scrum team at my job as a source of requirements driven from architecture. There is a woman on that team that I consider to be a rockstar.
At first I thought the reason she was being effectively utilized as a clerical resource was because the team had fallen into the “enforced mediocrity” trap that scrum teams often find themselves in. I thought that the criticism she would get at standup was universal. I witnessed her being criticized publicly by the scrum master for not helping out others with their stories that didnt make sprint. Meanwhile the tall outgoing athletic cricket player plays on his mobile 5 hours a day because he finished his tasks early and he never got called out.
I have had the product owner and scrum master ask me in private if I felt she was working out on the team. I was flabbergasted.
I made no small point to shame them. I told them in no uncertain terms that if she isnt working out it is because they arent utilizing her for the rockstar she is.
The next day they transferred her to a low impact team, which by the way is kicking ass right now while their team is failing so hard it is embarassing.