[Ichthypresbyter]

The same thing that serfdom has to do with monarchy.

In other words, nothing.

[crowselect]

Monarchy does not prevent enslavement. In fact, serfdom is a relatively common feature of monarchy. That’s what those two things have to do with each other.

[defrost]

The UK, under a monarch, abolished slavery and set the Royal Navy to blockade slave ships.

Meanwhile, the USofA pre civil war under a President with no offical monarch (other than the Little King for a term arrangement) had extensive slave plantations.

[quink]

There’s no serfdom anywhere in the world currently. There are plenty of monarchies in the world.

Meanwhile, currently, slavery is far more common in non-monarchies than monarchies.

Your “relatively common” is literally zero in the current reality, unless there’s countries you’re aware of that the rest of us aren’t.