Bought a VW approved MK 7.5 19 Plate Golf R from VW Derby with 44,000 miles September 2023 and paid less for it than similar are going now at VW Derby.
Personally put it down to how good the MK 7.5 is, VW took the really good MK 7 and just added enough touches and tech to basically nail it.
Opposed to the dogs dinner of the early MK 8 which are at least couple year younger, less mileage, but cheaper in some places.
Know many say they drive better than the MK7 series, but I personally would not take the risk on one due to the issues, and as MK 8.5 are obviously new and pricier, you look to the next best alternative, late MK 7.5's
Eventually the MK 8.5 will be the used option, and MK 7.5 will drop, but for now, residuals will remain strong for at least a couple of years.