No. because *none* of the mass effect timeline or logic makes sense. Earth doesn't become a galactic power in 27 years. And a private investor doesn't spend more money than *god* to build a colony ship that will never, ever connect back to earth. It's beyond logic comprehension that when 99% of the galaxy is unexplored vast numbers of people would sign up to leave everything they have behind to go on a one way trip that they don't even know will work - especially when we know that humans are already going into dangerous, unknown systems to build colonies not connected to citedal space?
Like I said, particular stickler.
First and foremost, what are you basing the
plausibility of the 27 year timeline off of? Other civilizations in the real world who, a hundred years from now, have found a technology-imparting monolith left behind by an ancient alien race, but took 50 years to get galactic civilization status?
Like 150 years ago we were on the tail end of the industrial revolution. Ever since then, technological improvement has basically progressed in an exponential manner. Throw in magical space aliens imparting magical space knowledge, some artificial intelligence, mass produced robots, and the sheer amount of raw resources that regular space travel affords you, and I really don't see how you can't find it plausible for humanity to get to the position they're in after 27 years. The question of "why aren't the rest of the galactic races, who've had a thousand years on humans, far surpassed anything we've achieved by then?" is generally answered by the notion of "they're still basing their tech on reaper technology, and that's the level of technology the reapers have set for any civilizations to achieve over the past couple eons".
Secondly, why would it be
impossible for a private investor to spend a very large sum of money to build a colony ship? You really can't envision even the slightest possibility for that type of person to exist? As we already know, one of the first people (Alec Ryder) to have set foot on the other side of a Mass relay is heading this thing, so he sure seems to have a vested interest in "going where no man has gone before". Who knows, maybe he got super fucking rich himself, and solely funded the mission? Or maybe some other (group of) angel investor(s) dropped some cash, and went on the ride themselves? Who cares, the point is that there clearly exists some crack in the notion of "It is clearly impossible for a person to exist who would want to fund this mission", some non-zero chance, which is really all you need to be able to tell a story. And that's disregarding any distinct possibility that there is in fact some specific reason for going.
And in terms of finding the people who would want to go on a mission like that, far more human beings than 20.000 have done far dumber shit for far less. Here's a little reality check: Two Hundred Thousand people signed up for the Mars One project, the one way trip to mars. Now, obviously only a fraction of people will actually go through with it, but the point remains that there is clearly
some type of person out there who would do something like this.
As to your last point, I really don't think you truly understand how big a number 10+ billion is. When you're talking a number that big, it's almost impossible to make a definitive statement about the statistical impossibility of anything happening. It is absolutely, 100% possible for there to exist ~20.000 (which is 0.0000002% of humanity, by the way) human beings out of 10 billion who would have the specific opinion "I don't care about finding another rock in this galaxy, I'd much prefer to go to a new galaxy, and be among the first to get there". Like, I don't understand how you can't agree with that notion unless you completely don't understand statistical probability. And beside that, we can't even relate what kind of resources such a mission might take. Like, how much is that really compared to what humanity can do? We don't know.
