That's the case for most ui/ux at a given point for responsive design, regardless of the ppi/size reporting. Also, I'm refering to text/font rendering, not UX

That's the case for most ui/ux at a given point for responsive design, regardless of the ppi/size reporting. Also, I'm refering to text/font rendering, not UX breakpoints, though I do understand the issue... the problem is, short of sniffing the user agent for "phone" or "mobile" there's no way to tell for sure... touch interfaces are unreliable as many desktops also have touch support. Note: I have used the phone/mobile sniffing to do some things slightly differently for desktop vs. mobile before. For the most part, it's not too big/bad of an issue.. I do know people that don't like certain sites/apps on desktop as this practice has changed though (namely, skype and discord) as a friend liked to use about 1/4 the screen for chat, but the ux now changes to phone ux when too small.