The clearest way to understand this market is to ask a single question of any company: who does this firm represent. A provider represents itself and its investors. A broker represents the seller and is a fiduciary. A marketing company represents neither, because it is not a party to the transaction.
None of those roles is illegitimate. The problem is that all three market themselves in similar language, with similar photographs of similar retirees, and a policyowner cannot tell them apart from the homepage. The companies that buy life insurance policies directory exists to label them.