I have made this point in a number of threads, though it is not a question of "identical" decor but of the QT being an established tank.
There is in my view a huge difference between a QT tank used for new fish acquisitions, and a "hospital" tank used to treat one (or more) fish for a specific issue when the fish need to be removed from the main tank for treatment.
Staying only with the new fish QT, it should not be a "bare" tank as the hospital tank might have to be, as this will further significantly stress out the new fish. If new fish are introduced to an established tank, with a substrate (sand or whatever), some "decor" like chunks of wood, rock, or artificial, that provides the fish with shelter, and floating plants (with or without lower plants), the fish will settle in much faster and with much less chance of developing ich or similar issues. It is assumed the water parameters (GH and pH and temperature) will be the same as the display tank.
Not only does the "established" QT calm the fish faster, but it means when they are moved to the display tank they will not be faced with another huge environmental change. Netting them over, and having to adjust to new tankmates, will be all the stress you want to inflict on the fish.