> Some would probably even prefer being beaten once in a while, than to have no hope of ever getting free of the debt after a decade of trying.
You are missing that slavery means your owner can beat you up and rape you as much as they want and you still have no hope of getting free.
Heck, if you just want to look at the Atlantic slave trade, the United States was _second to last_ among nations in terms of trade volume.
Also Native American slavery in the 1600s and 1700s was pretty huge (relative to the size of European populations) so there wasn't as much demand for African slaves until that "source" was depleted.
e.g. most of Carolinas and the area between Spanish Florida and English colonies up the coast was almost entirely depopulated largely due to slave raids (and at least by then the Spanish and English had a very different attitude towards enslaving natives so British-American colonies were somewhat unique in that respect).
And this extended to the North as well. Supposedly the proportion of households that owned Native American slaves in Rhode Island in the early 1700s was comparable to that in Virginia in the 1860s (of the average number of slaves per household was probably much lower)