I do get it, and I could have phrased it differently. My point mostly is, it is often painted as an insurmountable problem for adoption, and while that might be true for a lot of users, there's also a large number of user for who it isn't.
Also, for me personally, I'd rather switch banks than use a phone with a stock rom, but I know most people don't view things that way.
On my desktop, I have about 200GB free, which is about 10%, which feels like the bare minimum, and the only reason I haven't upgraded yet is that there's some large directories I can archive should it be necessary.
On my server, I recently was down to about 500GB free, also about 10%, which made me add more drives.
So it's all relative.