I feel like I live in an alternative universe to most people on here. In my world, ever since I've been shopping (and I'm 51 so been at it since the late 80s) polyester and viscose were commonplace. I can't remember a time where lower end shops like New Look, Bon Marche, Topshop, Dorothy Perkins, Bay Trading, Miss Selfridge, Oasis etc. which were my go to shops in the 90s, sold clothes in all wool, silk, or cotton. Back in the 90s my dresses and skirts were still all polyester, only summer sundresses might be cotton as is still the case today. Coats were always a cheap wool mix from these shops and suit trousers from Topshop and Burton (which my DH wore) were always made to be washable so definitely not wool.
My mum who's 80, will talk of a time when tailoring was always wool (and she was a tailoress by trade) but that was before the dawn of off the peg suits and coats and large hughstreet chains- she's harking back to the 1950s when they shopped at the local tailors and had a made to measure suit which they had only one of and it lasted a life-time.
Some of you on here are claiming polyester was rare 10 years ago and you were buying quality natural fabric clothing in all the shops. It wasn't. I agree, lots of shops have reduced their quality over the years- Next and River Island especially spring to mind. But it's over 30 years ago since I started shopping at Next when all their shoes were leather lined and made in Italy and their clothes were notoriously expensive and worn by young professionals on good salaries, and the shops were small and boutique like with carpet. Now, next is mass market and priced for the majority to afford and the clothes are cheaply made and the shoes are largely synthetic. This change did not happen in the last 10 years though.