I think long term humans won't exist anymore (beyond 300 years) but we will help create a new artificial/synthetic form of life that will actually be better than us. It's easy to think only in terms of humans because we have emotions mixed into it that make us want to see humanity continue. But imagine a form of life that is smarter than us, doesn't need food, doesn't get sick or have to worry about any illness or real physical threat except repairs or even full body replacement with memory swaps, no negative illogical emotions like jealousy or hate, they could spread throughout the galaxy much easier. No more starvation, plagues, etc. They would basically just be the highlights of us with none of the bullshit that humans come with.