You know. It’s actually rather depressing to see U2 give in to despair. They are a universe of Senshi tropes powered by love and they simply CANNOT compare to the shonen power of U7/U6 and the unstoppable Jiren.
It is a sad reminder, like when Gohan (unfortunately and unintentionally) executed another father fighting for their universe, that these characters are fighting for themselves, their friends, their families, their worlds, their UNIVERSE. This scene may be light hearted, but Ribrianne losing heart is indicative of the fact that she pretty much knows by now she has lost and everything she knows will be gone.
At least until the Super Dragon Balls restore it all.