Power dynamics in sex can be toxic or harmful, obviously. Like in anything. I’m generally sceptical of people who reflexively reproduce the power dynamics we see in society, i.e. men who just consider themselves naturally dominant etc. I think we need to constantly interrogate our own sexuality, particularly if it’s a sexuality that assets itself over others, otherwise we risk incorporating oppressive norms, practices etc into the sex lives of the people we’re with.
At the same time, I think it’s true that men are often expected to at least take the lead in het sex, and often be actively dominant. This is fine, but it does lead to men being socialised to become dominant when there are other possibilities and avenues they could go down, I think. And of course some people do reproduce the conditions of their own oppression in the bedroom, which is something we should be open about and accepting of, and work towards a world where everyone can engage in all aspects of life in a healthy way.
As with everything in society, we can problematise this stuff without declaring it problematic.