Supply and demand is an interesting point. Dealers have a quota, so in theory the demand should be controlled. Dealer runs out of quota and the order isn’t factory accepted till the next quarter; supply is regulated and the dealer has reduced incentive to offer a discount until they have allocation available again. Presumably dealers who work through DtD et al are using their quota through the broker so taking an easy route to gain business from a wider audience; arguably the lazy option, which may translate in to lower profit margins with a knock on to ie. staffing levels, but understandable. If they go over quota for a period the order isn’t factory accepted until the quota opens up again, whether they tell you that up front or not is up for debate.
What is a myth is that DtD et al always offer the best deal. They don’t. Dealers (direct) can and do match or beat DtD prices when it is in their interests to do so, presumably when they have quota left to use; it is fairly obvious that taking a third parties commission/fee out of the equation offers a little extra flex.
Whether buying direct or through DtD offers a better customer experience, I don’t know. But I can say that my current experience going direct to a dealer offered the best price and so far good communications, even if the dealer is limited in the availability of info they have to offer. My previous experience of buying a new Cali direct from a (different, West Country based) dealer was less positive, the price was also competitive but the comms were much less proactive, more pull than push. My only experience of using a broker (AutoEbid) was for a car and offered the best price, but the vehicle was in stock so lead time was less than a week.
Hope that helps add some balance.