You'd regret it!
I started out walking and backpacking at the start of the 80's with the philosophy of all-natural materials - nothing synthetic for me!
I had hand-knitted wool thermal underwear [thick and heavy], wool shirts [itchy as hell, and sweaty - anyone else old enough to remember the rails full of plaid patterned shirts in outdoors shops?], a pair of navy blue ex-police trousers that I got through Exchange & Mart [wool, again, warm and windproof but stiff and collossally heavy], an ex-forces "Woolly Pully" and - wait for it - I even had a tweed jacket, obtained from a jumble sale, at one stage. Waterproofs at that time were simply PU-coated over-the-head cagoules in which you became almost as wet from the condensation inside as you did from the rain outside.
With a combination of experience and the passing of time, with its advances in technology that have come about [plus my advancing years!], I have come to realise that for maximum enjoyment of the outdoors, in all that it can fling at you, and for maximum confidence, nothing but the best purpose-made modern garments of man-made materials will do.