Yeah, pretty much. Space travel and space colonisation are basically civilisation/world ending disaster insurance, which is something that's likely going to be needed more and more as time goes on. Want the best chance of not seeing civilisation wrecked by a solar flare/meteor/nuclear war/other disaster? Have multiple other settlements on other planets/moons.
There's also that point where the sun will become a red giant or something and Earth will physically be unable to support life, but there's at least 600 million years before that one becomes an issue, and I'm sure something would have figured out space travel before then.
It's like running a large website and using multiple servers/cloud hosting/multiple datacentres. Or hosting your site, domain and email at different providers. Makes it far less likely the whole system will collapse at once.