In the future, we will do a lot more.
In other terms: There will be a lot more work. So even if robots do 80% of it, if we do 10x more - the amount of work we need humans to do will double.
We will write more software, build more houses, build more cars, planes and everything down the supply chain to make these things.
When you look at planet earth, it is basically empty. While rent in big cities is high. But nobody needs to sleep in a big city. We just do so because getting in and out of it is cumbersome and building houses outside the city is expensive.
When robots build those houses and drive us into town in the morning (while we work in the car) that will change. I have done a few calculations, how much more mobility we could achieve with the existing road infrastructure if we use electric autonomous buses, and it is staggering.
Another way to look at it: Currently, most matter of planet earth has not been transformed to infrastructure used by humans. As work becomes cheaper, more and more of it will. There is almost infinitely much to do.