Is one who watches or subscribes to a da'wah channel on YouTube that publishes videos without music but sometimes includes pictures of women sinful, knowing that there is great benefit in it?

There is no sin in subscribing to the channel and watching its clips, but one must immediately lower their gaze upon seeing a non-mahram woman. A sudden glance is excused. However, if a person is unable to lower their gaze, then it is not permissible for them to subscribe to the channel or watch its clips, because warding off harm takes precedence over gaining benefit.