I don't think it's stupid to have a bit of perspective with your message.
They did not win because power of friendship, which would be a stupid cliché, but because they actually cooperated and cooperation beats individual power.
Much like with the robot contest where Pearl came out short but ultimately showed remarkable engineering skills, the message is not that you can do anything if people believe in you, which puts an enormous pressure on you because it contains an impossible assumption of success against the odds every time.
The message is that it's okay to fail if you try, that second place in a stiff competition is worth more than winning without trying.
And no matter how hard you fall, your family will be with you.
Steven and Amethyst fighting Jasper was them both accepting they can't beat the fact that Jasper is just stronger, but they sure as fuck can beat Jasper.
So they outmaneuvre her hard and win.
Because it's not about being the best. Only one can be the best and chances are it isn't you. So you have to win without being the best. By working together and setting your win conditions to where you can reach them. You don't win the game because you are the underdog, you win as the underdog when you keep playing and giving your best even if you lose.
Just doing it gets you places. And if you can't do a thing, learn to do it.
Rebecca mentioned a little strip her brother made about birds. Because he could not draw birds. It was shit but by the end he had taught himself to draw birds. This inspired her to make failing forward her motto in life and now they are making a show about it. Not to impress us but to impress themselves.