Recording equipment has never been better then what we have now. The larger problem is there is not that many people left that know how to use it. In the past you really had to be on top of all the technical issues to even make respectable recording. You had the plan it to even the type of music would alter think like tape speed, tape brand, and recorder calibration.
Today you have so much headroom and resolution you can completely screw it up and someone can fix it. DSP is very powerful and can do things that was only dreamed about 20 years ago. In the past every piece of equipment was very expensive and even the large thousands of dollars a day studios had their limits. In the past you might have processing on (eq's, compressors, gates, reverbs) on a dozen channels of the 24 track recording. Often you were trying to fix sound problem ( a little harsh, sibilance and so on) and you used as little correction as possible.
These days you have plug-in to do all that processing that took expensive equipment to do before. So many people use dozens of plug-in on every track and never if try listening if it need anything done to it all.
The significant effect would be put a great player with a great instrument in a great sounding room, know which microphones to use and where to place them, record it and if is not right don't process it with dozens of plug-ins just record it again.