"dollar pegged asset without actually holding dollars" This is probably the most succinct way to capture the concern. I wanted to point out that for sats earners in a world where bills are paid in fiat, you are going to be exposed to counter party risk. Bitrefill is doing their part with their bill pay program, but you can't force landlords to take it.

Because I closely know this mechanics I'd say no. With perpetual swaps funding rates are around 0 in the long run. Also provider may hedge with spot stables or fiat currency.

Such operators like Galoy may even use direct bank deposit to balance their position.