I don't wear jewellery, but I don't think matching sets are too matchy matchy. Honestly, I believe matching sets are meant to, well, match. I do own a couple of matching sets, and don't wear all the pieces together, but then again, if I ever wear jewellery, it's normally only earrings.
Matching sets are classic, in a good way. Maybe it's just a feeling, but I see that these days we regard matching sets -any kind- as something bad. Matching trousers/skirts and jackets, wrong. Matching jewellery, wrong. Matching cardi and cami, wrong. Matching belt and shoes and/or bag, wrong. Matching color shades, wrong.
Well, we could start wearing different shoes and sock for each of our lovely feet and start thinking that matching shoe sets is dated.
In the end, it's up to you whether you match or not. Personally I don't because that's just not me, but that doesn't mean I think it looks bad, wrong or dated. At all.
PS: Besides, you can go wrong matching a red shirt with green trousers, or a golden necklace and a silver ring. But you just can't go wrong with something that was meant to go together in the first place!