So how can a great system solve less than great recordings

   It would pay to do your "homework" as to what recordings sound best for each title you want in your collection. If you primarily spin CD's like yours truly you will discover that Original pressings in most cases are far and away better sounding than "REMASTERED" crapola from the past 30 years. Of course there are exceptions. Steve Wilson, Rhino Records and others are doing incredible work remixing/mastering master tapes from the 70's and 80's but thats less than 1% of whats out there.  Its a pain in the ass BUT it would be worth your while to get others opinions (Like on the Steve Hoffman forums as mentioned above). See what others are saying...then go to DISCOGS or EBAY and find those "best" pressings and slowly build your collection a piece at a time.  If your using a streaming service you arent going to get those original masters/mixes from back in the day. Your going to get the overly compressed/brickwalled/loudness crap that has plagued the music industry since the 90's.  Im sure for music made in the past 20-25 years the streaming services are as good as anything your going to get on physical media.  Always surprised how many people spend a small fortune on gear/cables/stands etc and then feed their systems inferior recordings when better ones are available. Makes no sense to me.

Yes, it was $13K, but the improvement in SQ with the Lyra Atlas SL makes ALL my record collection great. By pulling out so much information out of the groves, I love every LP. Sure, the rest of my front end is a match but a world class cartridge has brought a world class sound.
Now playing one of my two Better Records. Yes, it is a big step up.
OK, they are worth it. Now more than ever! Goes from the sound of humans to the sound of G-d. A religious experience.
But I still look forward to every “regular” record.

Lyra, a 13k cartridge, impressive. I suspect turntable kinda nice too.

Introducing my Woodsong Garrard 301 inspired me to upgrade every other component. It may not be the best but it has a drive and life-like sound that is addictive. Especially now with the Lyra, Triplanar arm and Atma-Sphere MP-1. The $28K MP-1 is among the only uber preamp that was designed to be full featured with phono stage dedicated to the ultimate vinyl playback.
With my AGD Audion mono blocks and Tetra 606 speakers, even with formerly poor recordings, I am in Audio nervana.

Everything starts with the source material. Anything after the source material is just masking shortcomings in the original material. While some equipment will help with the overall sound, I think you know how important the source material is. I haven't read all of the posts, but I'm sure people have given SOME good advice!