In the 100 to 200 year range, here is what I imagine (not predict).

We will eradicate poverty by eradicating the poor (and middle class, and maybe everything below the 1%) probably through some sort of opt in sterilization for cash program or maybe just by making healthcare and longevity treatments inaccessible to the masses, or climate change and economic pressure and a rigged system that only benefits the .01% will do it for us. Regardless, a lot fewer people and those who remain will be todays billionaires and their offspring.

No workers? No problem. Automation and ai will pick up the slack of the lost worker drones including all knowledge work. For those with the wealth and power to survive, it’ll be pretty sweet living.

We will have largely solved aging. People will be able to be treated for it like any other well understood disease. And for bigger things like organ replacement, we will have perfect, lab grown replacements.

Climate problems will be bad… for the poor. But they will be diying out quickly so no big problem. Some tech will be employed to mitigate and some of that will make the problems worse. But once below 1b people, we hit a turning point, the planet will begin to rebalance itself.

In 50 years I’d think deep integration between people and computers isnt out of the question. And by 100 years total social acceptance of people and computer hybrids should be possible. We would replace laborious processes related to learning with knowledge on demand. We would replace real world lived experience with memories implanted. We would manufacture feelings through chemistry. Our love affairs would be largely ai based and tailored to our wants and needs so more satisfying than the real thing (people won’t think of todays love as the real thing). Breeding would be largely a thing of the past with people using cloning in a lab for offspring and some gene editing to make them a bit different but highly tailored to our wants.

We will have permanent settlements orbiting various planets (space stations) in our solar system but not on-planet settlements because the resources to build a planet based dwelling are the same as a space station but the space station eliminates the gravity well tax. We will be mining asteroids for minerals (little robots will do that, not us). We will not be traveling that much faster than we do now. Maybe some sort of constant acceleration drive that gets us a few Gs of acceleration so we may have sent probes to close planets like Alpha Centauri, but not people.

There will be some who won’t want this new world but I believe they will opt out, choose death, or in some other way, simply fade away.