@wmorrow I think you pose a very interesting question. And with good questions considering the answer can be more valuable than the answer.
As I've upgraded my system I have questioned how much I've changed in terms of musical taste and appreciation of different aspects of music.
Over the last 10 years I've made three major upgrades to my system:
In 2014 I separated my audio system from my home theatre. My dedicated system consisted of NAD C375BEE, Dual CS 5015 turntable, Parasound D/HX 600 Tape Deck and NAD Digtial Tuner with Sonus faber Venere 3.0. Total investment (outside of the turntable and tape deck was about $7k. My living room served as my listening area and this rekindled my passion for music and I regularly listened to music for hours. I eventually added a Node 2i in 2018
I upgraded my system dramatically in 2020 after evaluating options with the intention of getting a much better digital experience. I upgraded several pieced: McIntosh C2600/MC 302, Moon 280D and Sonus faber Sonetto Vs and because I was able to buy some demos my total cost with buying appropriate cables was about $16k. The sound was significantly improved from my perspective - more detailed and increased dynamic range. My listening sessions increased in frequency and duration. I upgraded my dual to a Rega P8 in '21 since I have still have a few hundred LPs from my younger years. I also was offered a great deal to trade in my Sonetto Vs for Olympica Nova Vs.
Recently I upgraded again - I wanted a bit more power (I'm a former Field Artillery guy and often listen at 80dbs). I listened to McIntosh, Audio Research and others. I decided to upgrade DAC/Streamer, Preamp and Amp to Moon 390 and M400s. The equipment cost was $15k. Now if I upgraded my MC302 to MC 462 or even MC 601s it would have been $10-18isk...not significantly different in cost. However, I noticed the Moon amp was more detailed than the McIntosh system and was able to take advantage of a Moon trade in program.
Bottom line is I felt I received a significant upgrade in sound without a significant increase in price. The characteristics of the music system changed and I enjoy it immensely. Is my system significantly better? I think it is and I wouldn't be surprised if someone who had similar Moon equipment and upgraded to McIntosh.
So I think I've upgraded going laterally.