The Center for Investigative Reporting has, through its online publication Reveal, covered Amazon for quite some time - especially with respect to injuries. See:

https://revealnews.org/?s=amazon

A search for "Amazon working conditions injuries" on DDG or Google will return many of those, but also follow-ups by many media houses considered to be reasoned/reliable, rather than rabid and ranting.

Anecdotal, perhaps, but these anecdotes are there in significant numbers.