As far as a middleman or escrow is concerned, PARTICULARLY FOR PAYPAL, nowadays no middleman or escrow entertains Paypal, as nowadays Paypal is notoriously popular for notoriously accepting even notoriously fraudulent disputes (chargebacks). So, due to this reality that any of the parties can so easily "scam" another party in an escrowed deal where Paypal is used, no middleman or escrow nowadays entertains Paypal, ESPECIALLY if the product or service is digital virtual non-physical.
For a digital virtual non-physical product or service, Paypal will NOWADAYS even be quite glad to accept a dispute (chargeback) even for ridiculous reasons, for example : if a buyer merely says that the product or service delivered was haunted by a ghost at the time of delivery and the buyer sends proof to Paypal with a photo of a ghost watermarked over a screenshot of the digital virtual non-physical product or service. Paypal accepts such ridiculous & notoriously fraudulent disputes (chargebacks), because Paypal ITSELF is NOWADAYS quite popular for also stealing and scamming it's own (Paypal's) users DIRECTLY and such notorious acts of Paypal are all over the internet : just check on various forums and especially check about that on Reddit also.