Surely any rug or ourdoor furniture needs ideally to be moved undercover when the weather gets cold and damp, a rug left outside over the winter would be just one more thing to have to clean
It's good to have something soft to sit on in the garden when you can sit on the grass, well you can do now from the point of view of dryness but dead grass is prickly. I personally take dog rugs, blankets or sheepskins outside for doggies and me.
Plastic is so very hot though
At a friend's who has wheelchair ramps made of black rubber, in the summer sun they heat up so much, you could fry eggs on them
I have seen pictures of people's slabs that have been painted with patterns, which does look nice but not sure how hard wearing that would be. I've also seen on one of those garden makeover programmes someone continuing the internal tiles outside and thought that that was a recipe for broken hips when it rained
If I had a patio with a canopy or suchlike over it which kept things dry most of the time and that I could use more often than just the patio I might get a rug , if I do it will need to be one made out of recycled stuff, sadly most of our carpetting these days is synthetic.
I do wish that there was more ways of recycling some of the plastic that comes with modern gardening, pots and compost bags for example. Some british plastic recyclers take feed and fertiliser bags from Farmers who collect them in bulk, I'm sure that if it was possibl to do that with compost bags many would take their old worn out ones there, I have seen a bin in one garden centre but it was too far away to go on a regular basis