So far when I research the alleged problems with the US prison system, I learn they are also generally present in other prison systems.

There seems to be a general trend of "US inverse exceptionalism", i.e. arguing that the US is a uniquely bad country on the basis of very weak evidence. People complain a lot about systems in the US, but if you look at international comparisons, the US doesn't usually look too bad. Here in this thread people are up in arms because... 1/3 of Texas prisons have A/C, and the remainder have non-AC heat control measures. I doubt this is substantially different from non-US prisons.