I think the sweet spot for ARM SBCs are smaller, less powerful and cheaper for headless IOT edge cases. I use a couple of them that way when I need LAN connectivity, either by ethernet or wifi, and things wired to GPIO pins. I don't need a powerful CPU or lots of RAM for that. The SBC makers are caught up in a horsepower race and I just shrug, it's not for me.

This is my experience as well. I have a couple PINE64 devices, a Rock64 (Rockchip RK3328) and a RockPro64 (RK3399). And an N150 device.

Both ARM64 devices run headless, make use of GPIO, and have more than enough CPU. In fact, these are stable enough that I run BSDs on them and don't bother with Linux.

The Rock64 runs FreeBSD for SDR applications (e.g. ADS-B receiver). FreeBSD has stable USB support for RTL-SDR devices.

The RockPro64 runs NetBSD with ZFS with a PCIe SSD. NetBSD can handle ARM big.LITTLE well. I run several home lab workloads on this. Fun device.

I also have an N150 device running the latest Debian 13 as my main home lab server for home automation, Docker, MQTT broker, etc.

In short: SBCs are cheap enough that you can choose more than one, each for the right task, including IoT.