I did 'upgrade' it with more RAM and a much larger HDD (80Gb for the original 20Gb). Compared to modern flat screen AIOs, it's huuuuge! Loved it though. Iconic.
If you use it with older audio production software, it'll work fine, as it doesn't need the graphics processing power. You can still run multiple displays off it, you just don't get super high resolution. It has more than ample power for audio stuff. It's still a viable computer, I just don't have need for it any longer.
I may be wrong but I think if you install linux on it it can be repurposed as a server for some school, Non-profit, or even for home. But I wonder about the lifespan of the components, everything dies with time. I wonder if a modern Pi4 is more powerful than that machine 😆😆