The niche isn't gone. I know a small company that used a couple asus netbooks on the sales floor to work with customers to take orders (wedding invitations). As those asus devices died they were replaced with HP Stream 11 devices which I would consider to be the modern day equivalent of what we used to call netbooks. Even with a larger screen they are lighter and have better battery life. they have limited local storage, but the customer orders are stored on a local server so no need for a lot of local storage.
The/a niche for these still exists.