DBZ Head Canon: The Cell Timeline
In the timeline where Cell killed Trunks before going to the past, what happened? Well since all saiyans and androids are dead in that timeline.....peace settles on the planet. the people left are Bulma, Master Roshi, Puar, Oolong and some others I'm forgetting. Since no Z-fighters are there, Babidi doesn't come with Dabura to resurrect Buu since the original reason he did so was to find strong power levels. Omni-King doesn't destroy this timeline, because Zamasu never shows up. Supreme Kai and Kibito just keep pursuing Babidi to some other planet and find some other way of foiling him, since there is no real indication there is any power levels strong enough in that timeline to bring Buu back, or they just pursue him long enough that Beerus wakes up and hakais Babidi and Dabura, then hakais the buu egg easily. Beerus never visits Earth because the prophecy about saiyans doesn't apply, Freeza never gets resurrected by the Earth Dragon Balls, so Earth can rebuild, probably with Roshi or Bulma going to New Namek and getting the Dragon balls to restore what they can....and nothing else bad happens because all the bad things that happen tend to happen because strong power levels were on Earth. Bulma and Roshi are older, but the setting has essentially reset back to base before Goku became a thing.

the only threats we know that could still exist in this timeline are those remnants of the Freeza force from Resurrection of F. they are probably still doing evil, but considering that they couldn't find New Namek, and haven't found Earth in any future timeline, they might've just run into Broly on Vanta and got killed by him.

But then again, Broly's father might've been able to use the tech of the remnant freeza force, went flying through space to finally get off Vanta, and somehow crash land on Earth....another saiyan accidentally arriving on Earth, and Beerus receiving a prophecy about a super saiyan god but this time about Broly. Here We Go Again.....