You pointed out that a $1000 would take 200 transactions. Doesnt need to be that much, that could even be done with 1 transaction. And the whole point of an escrow is that you lower the rate of being scammed.
Before completing the escrow and that Dream could release the fund by sending it to the seller wallet is done after both parties( seller and buyer ) confirm the escrow that the product or service has been shipped and recieved.

The fees are low just because the  3%-8% usually take a lot of profits from a high amount of escrow. Dream lower the fee by using less transactions i guess.
correct me if im wrong