Blu-Ray/4K player or stream from Amazon Prime/Netflix

So I'm new into building a home theatre.perhaps I'm stating the obvious...but is still buying actual discs better to watch on a home theatre versus streaming online? Is there a quality/sound difference? 

I have had three theater rooms and I just recently built my last one.  I am all in on Streaming now. In my last hole, I had an OPPO 105D player and I never used it.  Save your money and put it into a room acoustics and a great projector.  
Video quality on 1080p Blu-ray and 4K Blu-ray is usually significantly better than 1080p streaming and 4K streaming respectively. A lot of times 4K streaming looks like well upscaled/post-processed 1080p Blu-ray video. There will not be as much of a difference for some titles if the disc is heavily compressed to fit more episodes on it.

As for audio, you may or may not notice an audible or obvious difference between streaming or disc, but streaming is almost never lossless and sometimes dynamically compressed under the assumption it will be consumed in a nosier more casual environment.

Personally, if there is something I care about I will get the disc. If it's more casual viewing then I will stream it.
Quality marginally better on disks. Not worth the time wasted in finding, loading, fighting off previews and waiting for stupid menus IMHO. 
I only watch dvr’d and rips. Rip ’em on the computer and watch anywhere.