To be clear, I don't think Superman has been emasculated or "beaten" by Supergirl. That was never my concern. Don't label me as a "man baby" or whatever term is popularly applied. To the contrary, I'm a big fan of the show and Benoist in particular, and I feel her portrayal is and will be looked at as THE iconic one for Supergirl/Kara in the future.
My concern is that he is not nearly as strong as he should be, and this also applies to Supergirl, who the writers have also written poorly. Both characters should be stronger in terms of power. I don't care that Supergirl beat Superman in a fight; I do care that regular (augmented) humans beat both of them down regularly in the series (often without the presence of kryptonite), and I also care that both are shown to be increasingly mundane in terms of tasks accomplished. These characters should be allowed to do astounding tasks more often by the writers; give SG the opportunity to demonstrate her powers, and if you have SM in a guest role, give him similar opportunities to do so as well. SM should be more authoritative and assertive, with OR without the presence of SG. I feel like one of the biggest missed opportunities they've had was having an episode(s) centered around SM and SG disagreeing on the proper course of action - these are both very strong-minded characters in theory - and seeing how they would work through their disagreement. Luckily they still have a chance to write this storyline with the new SM series.