Quality is still an issue for streaming. Anyone who's ever compared a blu-ray to what Netflix offers knows it's night and day, especially for grainy old films. Netflix so-called "1080p" frequently has compression artifacts, and banding (most visible in dark shots). There's also disturbing aliasing (most visible in logos and on-screen fonts, causing jagged edges) which is more reminiscent of DVD-era MPEG-2 encoding than modern codecs. I'm constantly put off anytime I find a title on Netflix the minute I compare to it bluray screencaps (good resources are blu-ray.com or caps-a-holic) and notice the glaring contrast in quality.
And this is only for the titles Netflix offers in HD: there are many, probably due to licensing issues, which are offered only in SD resolution (which can be confirmed during playback vie the web player debugger). Netflix originals, while seemingly having the most consistent quality, still suffer from poor encoding issues I've noticed, which makes me think most of all that this is aggressive bandwidth management if even their own titles aren't given a proper encoding treatment.
And then for 4k playback on PC, it's required you have not only a compatible browser or app (4k playback in Firefox will not work), but also a recent CPU that supports hardware DRM - just awful. The future of streaming is bleak if you ask me, albeit convenient for the average consumer. And I guess that's the real demographic.