I think it can be quite difficult to imagine yourself in a place if the decor has a very strong slant to it - taxidermy collections, purple everything, that sort of thing. Or just clutter in general, so you can't get a feel for the dimensions of a room.
Our previous owners (we just bought a few months ago) bought the house in 2016, and I was able to track down the old house listing photos, they hadn't done a lick of decorating in the intervening years, it kind of blew my mind. We're now living with 90s swag curtains and manky old carpeting until we can get around to redecorating; there was a lot of basic maintenance they didn't do, so boring jobs like repainting the wood sash window frames etc comes first.
My own buyers were FTB and had an overlap between their rental and our completion, their plan was to redecorate loads of rooms before moving in. So they could clearly imagine the space done to their own tastes! We worked hard to keep things simple, uncluttered, and homey though.