The other thing though is taste is subjective. Very few people decorate or furnish simply because something is fashionable, so many things are fashionable, it’s generally because folks genuinely like them also.
Things that are truly dated are coloured bathroom suites, Artex or woodchip wallpaper, solidly coloured (red, blue etc) or patterned carpets, certain wall colours like peach, magnolia or terracotta, feature walls with inexpensive big patterned (often floral) wall paper, carpet in the bathroom, orange pine furniture, farmhouse orange wood kitchens, short curtains, net curtains, plastic Venetian blinds, With wooden worktops, gas or electric fake or bar fires etc, so either sixties, seventies or eighties. Which is let’s face it is decades ago.
What’s fashionable now is self coloured fix and fittings, muted Non clashing pant colours, expensive Funky wallpapers, luxury textures like velvet or silk, painted kitchens With metal over tones,Ie copper, aluminium etc, islands, hard flooring with thick piled rugs, large throws, candles, soft lighting, long curtains, Luxury blinds ie velvet, silk, hardwood,, shutters, wood burners, etc.
However everthing becomes dated after a while because it gets old. And when things get to about twenty years old they start to then the corner and become dated the longer they are in place.