The earth in the other universe is completely destroyed. Absolutely no life left. Goku didn't even consider that. Goku had gambled before....but that's mostly on his ability and belief in others. But he absolutely doesn't care in this case. He just wants to fight stronger people
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Beerus gave Goku and Vegeta an out....these dudes didn't even blink an eye. Yes they are competitive, but they've always put the safety of earth first before anything else. For Beerus to ask Goku if he's ok with the tournament and the risks....and Goku to gleefully say yes without thinking...is a lil out of character. Maybe it'll dawn on him what the stakes are later.
Maybe they're just old and senile now
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