Most people do not want to go out and buy new hardware to run a Bitcoin node. The want to use the hardware that they already own, and usually that hardware is going to have a non-generous amount of disk space. 500GB SSD with no HDD is common in computers today.

But really, the best test is to go out and talk to people. Ask them if they run a full node, and if they say no, ask them why not. In my experience, the most common answer by a significant margin is that they don't want to lose the disk space. That psychology is far more important than any example of cheap hard drives. People don't want to go out and buy a hard drive so that they can run Bitcoin. It's a non-starter.