The link you decided not to follow gives a lot of context. Although in French, which I do not speak.

These people weren’t murdered at Dachau. They are being cremated there, after dieing aboard the prisoner transport train from the Royallieu-Compiègne internment camp.

The German Wikipedia about the Sonderkommando photographs describes those as the only surviving photos taken by prisoners inside the camps.

No; in a free market without regulation. the bigger fish outcompetes the smaller ones, or buys them outright. Which then is exactly why enshittification works in the first place.