First, I want to be clear that in the sense you are talking about, I fully agree with you.

But "work", in the sense that AI can, in theory, replace humans in, is about more than just jobs. It's about many of the things that humans do—including many that we do for pleasure as well as for money, like painting, writing, and other forms of art.

In that sense, it absolutely does bring dignity and purpose to people's lives. Very few people can feel fulfilled without some form of work in their lives, whatever that looks like for them.

You are talking about intrinsic vs extrinsic value. Most work people do is for money (extrinsic) but no one is stopping you from doing work for the former. I learn/program for fun in my spare time and AI doesn't stop that.

I’ve not met anyone who defines “work” like that.