Who is providing true 4K streaming? And by that, I mean a stream quality that can improve upon a 1080p stream of the same bitrate, we are talking about 50Mbps at least, Blu ray bitrates, something like 75-100Mbps. Netflix caps at around 16Mbps, it is more of a 4K placebo.
Otherwise, there is really no point to go with 4K, you can find lousy encoded content for any resolution. There is a strong trend in underground rips to provide highly compressed 1080 content that looks more blocky than its 720 equivalent of the same total file size.