A "motherfucking website" without any css nor js is perfectly readable and usable on all devices and browsers. Users can select their preferred font sizes, and even colors. It is just like an ebook, that is readable everywhere, and responsive with user-chosen display setups and settings. What is the problem, then? Some websites want to look "fancier", and then they specify styles in manner that is incompatible with some usage patterns? This is an entirely self-inflicted problem. The problem did not exist in the first place, they created it.
I have real trouble accepting that "web design" is not a bogus and fully useless human endeavour. I hope someone around here enlightens me to the contrary.