Most of us often "upgrade" simply because we can, not necessarily because we have a need. Since there's not really a whole lot of innovation going on with amplification, loudspeakers, turntable systems, or even a UNIVERSAL high-resolution digital format, we focus much of our attention to accessory products that are new, at least aesthetically.
The profit margin on cables is obscene. Other tweaks are often the same story. Expensive fluids, cones, rollers, clamps, compounds, connectors, etc. are all for-hire in the audio whorehouse. Get your cash out folks, it's time to tweak...