I don’t think you’ve gone astray at all. It sounds like you’ve built a solid system! Here's a quick overview of my setup, which might help as a comparison or give you idea:
System Specs:
CPU: Ryzen 5 2600
RAM: 80GB
Boot Drive: Cheap 500GB NVMe SSD
Graphics: RX480 for system display, a 3050, and a Quadro K2000
Connected via an HBA:
System Pool: 2 x 1.8TB SSDs
Mass Storage: 4 x 8TB HDDs
What I Use It For:
Jellyfin
Immich
Home Assist.
Compiler for FPGA development
VMs
Game Servers
Plus a mix of other tasks and projects