If you define slavery as a transaction such that a human financially pays another human to own a human - then - slavery is alive and well - now!

How?

Stocks.

When I purchase stock in a company comprised of human beings creating a product or service to be sold for a profit - I purchase human beings. Do I own the life of every person in that business? To the degree my stock dividend(s) diminish their pay and or benefits - yes.

So!? Slavery is alive and well for as long as humans buy other humans' time, energy, skills.