They're not an "absolute loss" since they cost bytes to store, and raise engagement and data metrics.

It's just that they don't want to share the fractions of pennies with everyone, so the fractions accumulate for them.

Then they pay a bit to the higher tiers, so they create the illusion that X is a parallel income source, and gives the lower tiers something to aspire to.

Carrot and stick, or rather glass beads and the hope thereof.