The Raspberry Pi 5 and Orange Pi 5 are just too expensive. I do have some of the Pi 5s from both these companies, but have replaced them with Intel N100 mini-PCs instead. But I'll still use RPi 4's for my 3d printers and other lower-end uses.
And RPi's software support is just better: I've got an Orange Pi 4. Orange Pi hasn't updated their OS for it in years. Last time I tried to get it working in Armbian, HDMI output was (is?) broken: https://forum.armbian.com/topic/26818-opi-4-lts-no-hdmi-outp...
For me personally, much of the value of the RPI products is knowing they will have long term support.
RockChip really only appears to care about embedded auto apps etc...thus their support horizon is more about sustainment and not enhancement, and they do little to support the community.
I can get this for the RK3588 though there are problems with my Orange Pi board that uses it.
https://www.reddit.com/r/OrangePI/comments/1buzts4/uboot_v20...
It's an archlinux PKGBUILD that applies a couple patches for the device drivers and HDMI. This can probably be repurposed to build on any linux distro. Obviously flash your firmware with caution, but it's been booting from SPI to NVME without any issue for a while now.
If there is more interest in this, I can fully flesh this out.
The board boots Armbian fine with nothing connected to the serial port.
[1] https://github.com/Joshua-Riek/ubuntu-rockchip/issues/1073