and all other parts of the world, honestly

so the supply never dried up, just the demand was outlawed.
if there are buyers, there will be sellers.

explaining it to a 3 year old, i'd mention it wasnt africans selling each other to europeans (how we see it now), as much as it was country A selling war prisoners/generational enemies from country B to traders/pirates from country C. and then raids/kidnappings to keep the supply going.


as for tactical, technical, technological advances
europe had 500 years of practice in warfare and subjugation in their quests for power
and african nations were ripe for division and manipulation in their internal quests for power

another common misleading thought is that "europe enslaved all of africa" in the sense of some white dudes steamrolling thru an entire continent, when really they never made it far inland. to this day some places in the interior talk like they barely knew slavery happened, like it was just a rumor of something far far away