They are chasing the sales targets, in NW they are offering to show the at cost invoice + £1 -again.
It should be illegal to say they're doing that. Dealers get all kinds of support, bonuses etc, behind the scenes. I refuse to believe that my local 'glass palace' dealership isn't getting a LOT of support from Honda - the place is always deserted and there's no way the business makes sense in any normal way.
Why buy new these days?
I'd say to keep an open mind. Car factories either need to work to full capacity or be shut down, so when they're working those cars have to be sold. Often there will be hefty discounts and (especially if buying on finance) subsidised interest rates and maybe a deposit allowance. Add in free servicing and maybe extended warranty and it might make more sense to buy new than used.
I don't normally bother with finance but on our 2014 Jazz we got 0% APR and a £500 depositi contribution. Salesman told us all manufacturers like to get people onto PCP as it's easier to move them onto their next new car then. We also got 5yr service and warranty and a chunky discount.
However I still didn't feel we got a great deal. I was buying the car for one of my daughters, if it had been for me or wife I think I'd have walked away. Indeed we later changed wife's Jazz and went for a VW instead - another brand where new was certainly cheaper than nearly-new.