Ozzy, Rainbow, Lizzy and my beloved Status Quo etc. Their early material just doesn’t ’cut it’ on a high end system (IMO) and I find it more fatiguing to listen to. Modern technology and attention to detail in the recording studio has really dated some of my favourite bands to the point I find it harder to listen to them.
Get yourself a pair of 70s speakers for a couple hundred dollars and listen to Ozzy and his brethren through those speakers. They should be sufficiently non-audiophile for you to enjoy your music. If that doesn’t do it, try buying a 70s receiver next.