Not sure what you think PPI means or how it’s calculated, but it has nothing to do with being a tv or a monitor. It’s a relationship between the number of pixels and physical size.

A 34" 1440p monitor will have a lower PPI than a 4k TV at the same size

Pixel density is pixel density. Doesn’t matter if it’s a tv or a monitor.

Sure monitors typically have less input lag and there are reasons one might choose a monitor over a tv, but the reverse is also true. I chose a 55" tv for my sim racing setup that sits maybe a meter from my face and there’s no problem with that setup