Thinking about it... ...shouldnt it exist a timeline where the timemachine was not invented? Future Trunks messed up future with undefeated Androids and a Cell waking up
That's not the way it works. There's not an infinite number of possibilities running concurrent to each other. Bulma fractured the timelines in the first place by inventing the time machine in the original timeline.
Bulma, the true antagonist of Dragon Ball Z. Does Majin Boo even happen without the Cell games. Like wasn't he a consequence of how much stronger everyone had gotten, because Bibidi realized there was now enough ambient energy in the system to summon Majin Boo? Like, what even happens in a setting where the time machine is never made?