There is not the slightest doubt amongst professionals that the the best picture and sound quality were in movies and music filmed and recorded in the late 1950's and 1960's..
Can I disagree here? Analog was not a great recording technique for films.
In the 1970's, mass production of cheap cr*p started and replaced the hand made professional equipment of the previous era - poor sounding transistor mixing desks, film processes with less accurate colors (not to mention houses and cars that were the worst ever made).
One could easily argue that the consistency of the gear was a good thing. At least you always knew what the limitations were.
Digital picture and sound have helped that m the 21st Century, but 35mm film stock has way more resolution than 1080p digital video...
These two are orthogonal. It's been quite a few years since capture was made via analog for audio tracks.
PS If HDNet-Movies and Voom send DD5.1 for 30+ year old movies, then that is incorrect. If the movie is DD2.0 or DD1.0, then one is supposed to allow the receiver (and the user) to respond to that in a different way than a DD5.1 input.
Bravo on this point. I agree wholeheartedly.