TeslaOff the top of my head, I can't think of any manufacturer that will sell you their product at reduced / wholesale prices if you buy directly from them. I'm thinking phones, cars ... maybe there are but I can't think of any right now.
Nike
Adidas
Dell
Apple
Ryanair/Aerlingus/etc.
Dyson
The internet has changed things, you can buy whatever product you want directly from a manufacturer.
For the financial services industry, it should be even easier than for physical manufacturers.
I agree that a good financial advisor or broker is the best option for a lot (maybe the majority) of people. But not everyone needs advice.
Specifically, for PRSA's, to my knowledge, you can't go direct to any provider. If you want to invest in passive index funds in your PRSA (as opposed to the lifestyle strategy), then the only differentiator between providers is fees.