Answer:
Perfect competition is only theoretical, it does not exist in the real world. Not even commodities markets like corn, soybean, oil, etc., work in a perfectly competitive way. First of all, taxes, tariffs and subsidies exist. Also, one of the conditions for perfect competition is that all buyers and sellers must have immediate access to perfect information, and that is virtually impossible.
Perfect competition markets act like benchmarks since real life markets will never be able to reach perfect allocation of resources, but some markets get really close to doing so.