Depends how you define "plastic". There are a number of really nice carbon fibre fiddles in the "serious" price range that may give up a teeny-tiny fraction of

Depends how you define "plastic". There are a number of really nice carbon fibre fiddles in the "serious" price range that may give up a teeny-tiny fraction of the absolute best that can be achieved with the best woods, the best varnishes, the best luthiers, the best alignment of the stars and the correct sequence of profanities and vulgarities uttered during the production process, but for that minor loss you get excellent instrument-to-instrument consistency and the ability to play with the same sound under wildly varying conditions of temperature and humidity. Part of the problem with acceptance is that once the price gets high enough, people want "a real one", and Cremona never smelled much like carbon fibre. Boosey & Hawkes used to make a wonderful series of woodwinds (clarinets and oboes) in aligned glass-fibre-reinforced resin with the same sort of advantages - and disadvantages - with one extra little niggle: they weighed a bloody ton. (I owned a B&H clarinet I haven't picked up in a little over 20 years. There's still a discernible dent in my right thumb, something one never got in a persistent way from wood or the student-oriented plastic or Bakelite instruments. Much nicer sound than anything of wood at twice the price, but I can understand why they didn't sell too very many of them.) I'm sure they could do much better now, at a cost - but then there's the acceptance factor to deal with. At least ebony has problems associated with it that spruce and maple don't so far; it will probably be easier to accept good synthetics over bad or hyper-expensive wood before too much time goes by.