Or that there simply is no need for that high a bandwidth. Netflix, e.g., uses fancy compression algorithms and you can almost watch their HD offerings with ~3mbps. They do recommend 5mbps and 25mbps for their 4k content.
I so wished, I could get here a 6mbps connection for half the price of my current 65mps line.
I know that there is use for it ("any space will be filled"). A buddy of mine has two teenage boys -- 'nough said. I just don't see that as explaining the market for 100Mbps+ connections to the home and such routers.
Your use case reminds me of the (mystical?) fellow who allegedly complained that his new graphics card didn't allow him to play his favorite 3D FPS game and watch a movie simultaneously.
I do this. I watch Netflix and play video games at the same time. So I guess my point is this is a use case which exists. My GPU handles it just fine though.
Another point is that old wireless tech is inefficient so it reduces your smartphone's battery life. Faster connection able to work faster, so the device can go to sleep state early, even when streaming Netflix.
You might not have a need for it but others do. It really sucks to buy a new game after work and see that you won't be able to play it that night because it has a 5 hour download time.
I so wished, I could get here a 6mbps connection for half the price of my current 65mps line.