Resources and population will both remain finite, fear not.
Even here on only Earth, there are more than enough resources for several times more human beings, and more resources are produced on a regular basis thanks to the sun.
That’s a classic tech will fix it narrative. The likelihood of us making it off the planet at a scale that matters to common people is basically zero.
It’s arguing on faith that we will move of the planet to defer living sustainably on the one we have which is a classic ruse to e able people to rationalize not changing lifestyles.