Why nuke us from space when we're the best reality show in this corner of the local cluster?
update: one could argue that the advances in medicine which have increased the average human lifespan considerably in the past 300 years (double?), amount to evolutionary biology, in that with vaccines we are able to "evolve" our bodies to resist diseases that killed millions in the past.
Real aliens might look at us the way we would look at a raven using tools. It's cute and novel, but not exactly scary. It's either pure hubris, or drama for the sake of a story that doesn't end in the first 2 minutes, to assume that humans with little bottle rockets we can barely use to defend ourselves from rocks in orbit around us would stand a chance against any species advanced enough to physically cross light years of distance to show up here.
The reality of a species reaching interstellar travel will be any other species will be dozens of millennia of years ahead or behind at most.
This of course doesn’t allow the allegorys that trek is famous for.
If we spread to an neighbouring star system then we can spread to 50, then I don’t see what will stop them from continuing to spread, to the point the whole galaxy is occupied by future mutations of humans, or solar systems completely drained of resources.
But I don’t see humans having the drive to actually spread beyond Earth before the end of modern human civilisation (be it war, plague, ai or technological regression)
There are several instances where starfleet finds species that are vastly more technically advanced. Q are a notable example. There isn't usually much interaction with them though, sometimes the humans are told outright that they just aren't ready yet.
There are also many instances where they find species more than 500 years behind. As a matter of policy they try not to interfere with those species, but they do research and monitor them sometimes. They are species too far behind technologically to have developed warp technology, but far enough advanced to make it into space on their own and species who weren't advanced enough to make it into space on their own but ended up there anyway. Ornarans started off being a technically advanced pre-warp species, but all that knowledge was lost leaving them flying around in ships they didn't understand enough to make even basic repairs.
Speed of light/information, and physical matter.
In that case you can repeat it using the resources of the next system to hop to the one after that. Might take 500 years before the next wave, might lose half of the systems to internal strife, but it only takes a couple to start growing and due to sore of light these systems would be separate civilisations.
Still, I clearly failed since everyone is interpreting my scenario literally.