Other boards beat the Raspberry Pi in mainline kernel support, USB & Ethernet I/O & price years ago, but there is a significant ecosystem that the Foundation seeks to support, and the best way they know how to do so is with the tools they are intimately familiar with.
You sound knowledgeable, so I'll ask: if you don't care about the RPi ecosystem (or IoT use-cases at all, really), what's the optimum SBC across all those axes currently? Like, what board would you choose to base a cheap one-off HTPC+NAS on?
For a NAS, nearly all of the OrangePis feature USB ports & ethernet that are directly wired to the SOC, so you aren't I/O limited like older Raspberry Pi's. That being said, the Allwinner H3 doesn't support 10 bit Hevc/H.265 acceleration, so you might want to go with a board based on a newer chip for a HTPC. Take a peek at LibreELEC, they have a decent HTPC distro for many SBCs.