My first port of call is always Netflix. When that doesn't have what I'm looking for I resort to streaming sites.
I never watch films or TV on my phone, but if the intent of consuming media is purely for entertainment purposes, then I don't see why anyone should care how it is consume.
If you want to make a case for artistic and critical viewing needing certain platforms/quality/device, then sure, go ahead, but most just wanna watch some good ****.