That's maybe true, but just think about it, Tatsumaki could shine this time and other heros too. It's also better to just focus on the main character who is obviously stronger then all of the foes. It will become boring if the same would happen and there is no real threat for him and he is always everywhere to help.
Besides he is still a C Rank and obviously no one from the association know about his true power, so they won't let a c rank to interfere, if he ever made it (the other heros won't let it too). I get your point, it is frustrating to know the one who can save them is not there, but I think there would be a part where Saitama will shine in front of them.
While those heros are struggling saitama is just vibing somewhere.