Lol at everyone saying "don't even use Minato to prove your point, he's not even an Uzumaki". That's not what is trying to be said. Minato literally is not part of any special clan (as far as we know) and he literally has no built in power ups AT ALL. The only things he has are the crazy jutsu he created, and a lot of those center around, guess what, yeah, sealing.
So, if Minato, a no-clan ninja, could become so powerful with sealing jutsu (and also rasengan, but let's not underestimate the power of sealing) then why should an actual clan like the Uzumaki's be weak? They have these specific clan sealing jutsus, tons of chakra (which allows them to use powerful jutsus to a fuller extent, or fight on for longer), strong life force (even if you refuse to believe it), etc. Of course, in every clan there are gonna be weak and strong ninja. But if an Uzumaki ninja trained and utilized their sealing jutsu, it's not as if they'd be fodder.
If you really wanna come down to it, there have already been two main characters, Naruto and Nagato, who are Uzumakis. Yes, like you said at the beginning they have other power ups (kyuubi and rinnegan) but do you think Kishi would make two important characters bearer of the name of an insignificant clan? I still think there is more to be revealed on the subject.
