Here's a reproduction of my issue (codepen because apparently stackoverflow's iframe affects the rendering somehow):
https://codepen.io/Ironimus/pen/GRjxpXZ
When using transform: translateZ and perspective inner elements' edges and text become blurry. It works very differently in different browsers, too. In case it also depends on screen or OS, here are a few screenshots with descriptions:
In Google Chrome transform: scale(2) is fine. Text and inner elements become blurry depending on the width of the element with perspective, and it follows very strange logic, when I set the width to 847px or higher it breaks, lower looks ok:

In Mozilla Firefox text becomes blurry if perspective/translateZ combination is used, inner elements are fine, transform: scale(2) is ok as well. width doesn't seem to affect anything:

In Safari everything is hella blurry whatever I do:

Why is it blurry at all and how do I make it right? Using transform: scale(2) for everything isn't a viable option. Are there maybe some rules I should follow to help browsers render 3D transforms with text right?
Supporting Safari isn't a priority but would still be nice
Have you tried adding a custom -webkit to the browser?