There's numerous direct primary sources who were alive at least until the 1990s about what life was like in Tibet. It is only because this is such a politically contentious issue that the wikipedia page is "both sides"-ing it.

The only source they have in that article that disagrees that amputation and gouging of the eyes was a routine punishment was a literal Nazi.

The overwhelming weight of evidence, even in that wiki article, is towards Tibet having a feudal society with routine amputation/gouging as punishment.

https://infogalactic.com/info/Lungshar - had their eyes gouged out by the state