Interstellar space travel and two way communication between them is the largest barrier. So multi system is going to mean multi planet in our solar system probably for a very very long time. Otherwise it’s just sending cryo pods out into the nether without ever knowing if they made it anywhere for the centuries it takes something to (successfully) come back.
We won’t ever send physically natural humans to other systems.
Not because we could never do it, but there won’t be any motivation to.
We will send relatively tiny ships, initially as probes, then as resource extraction & reproduction systems.
With laser acceleration & fusion deceleration (potentially fed by hydrogen collected collected from the target system), travel between systems can happen within 1-10% of the speed of light.
So only ten or so years to the closest systems.
That (propulsion) technology is not far off now. The bottlenecks are the need for further miniaturization, and our economy could not yet support the cost of, nor is it ready to benefit from, that scale of investment.
Whatever “format” our technology/lifeform has evolved to, we will be able to be sent it in extremely compact form, given any thing large can be recreated at the destination.
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Ironically though, despite a decade or so sounding very fast to us now, with time deflation (I.e. absolute time translating to higher & higher subjective time as “we” and our ability to process information & act speed up), decades between systems will subjectively Become be aeons of time.
But resource needs will also accelerate, so the necessity will be there.
So space will be deflationary, along with time. A meter & a second today will have much more relative meaning in the future as everything becomes more compact and faster.
Think about how the digital latency around the planet remains a constant, but as computing centers increasingly compactly, and grow in processing power, by orders of magnitudes, distributed computing with any serial or regular merging component will have to become ever more & more local.
Mars is big latency today. In 50 years, cross planet communication will be a relatively big latency.
Where's "10 or so years" come from? Proxima Centauri is over 4 light years away. At 10% light speed, that's ~40 years minimum. At 1%, over 400 years. We'll ignore any time needed to accelerate and decelerate. It's a long time. I hope someone still remembers the project exists.
