Regarding a dealer group structure, advisers and business pay either a fixed fee or percentage of their revenue to the dealer group for services rendered (using their templates, HR, compliance checks etc).
Dealergroups used to be able to make a significant amount of money from volume rebates (amount of product recommended by the advisers under their banner) as well as receive shelf space fees (product providers having to pay them $$$ to be on the approved product list for the dealer group advisers to use). These are no longer available and profitability gradually reducing accordingly, making them more reliant on charging fees to advisers.
More and more advisers are moving to their own AFSL as they find their dealergroups need to either charge them more, or cut down on the quality of their service to survive. As time goes on having your own AFSL is becoming far more common and its very cost competitive, in many cases, actually cheaper. The less advisers within a dealer group structure, the less they make again.
Furthermore, due to the upcoming professional exam and degree requirements for advisers, I anticipate the overall number of financial advisers will reduce dramatically (it already is) as they sell their businesses. Those hit the hardest are the older advisers who aren't really qualified past a simple diploma and don't see the value in going to uni to complete a degree... Those advisers are mostly in dealer groups...
Hope that helps, simple article below on the movement to own AFSL.