This is quite a simplistic view. Slavery in its milder forms (buying and selling people along with land, restrictions on movement etc.) was widespread in Europe

This is quite a simplistic view. Slavery in its milder forms (buying and selling people along with land, restrictions on movement etc.) was widespread in Europe up until 19th century. There has not been a homogeneous class of “white people” who universally benefited from slavery. Secondly, there is a distinction between considering something “evil” and “unnatural”. My ancestors clearly hated the German landlords but, at the same time, clearly saw the situation as something quite natural. After all, it had been the fact of the matter for 600 years. This is further evidenced by the fact that it took more than a century of gradual awakening to actually realize an alternative social structure. So, by the standards of about 200 years ago slavery in these parts was certainly not seen as desirable by the slaves but quite certainly as something “normal”.