It would be better if the basic hardware — serial ports and such — was in a standard location for all RISC-V machines, and all the rest of the hardware was discoverable at runtime (like PCs, mostly).
On a PC, there is a serial port at a standard location. It's not "discoverable", but every PC you care about has one at the same address, and it's incredibly easy to use with a tiny bit of assembler. You can always print messages, even in the earliest parts of early boot.
On non-PC platforms (I've used ARMv7, ARMv8, POWER) there's a zoo of serial ports. There are at least a half dozen different bits of hardware, on different ports, self-describing, not discoverable at all, or mentioned in device tree in multiple different ways. Some even require PCI so needing ugly hacks to output early boot messages.
Critically, if you get the wrong serial port, you cannot see any boot messages at all. There's no way to tell what's going wrong.
So I think, for serial ports, the PC approach is definitely, clearly better.
For other hardware, it should just be self-describing. PCI and USB are the model examples here. And in fact, why not just use those?
If RISC-V does this well out of the gate (like with IBM's old school Open Firmware) and has great shiny device tree support, I think we might end up like x86 -- where a single thumbdrive can boot almost any x86 machine under the sun.
Device trees are needed because manufacturers did not create self describing hardware.
This is impossible to do beyond trivial components. Most devices are complex systems of interacting components.
Also, do you want the same lazy manufacturer that couldn't bother to create a device tree create a complete hardware description ROM and get it right in the first attempt?
It would probably force the hw manufacturer to think through its design a little bit more, which would be a good thing. I've seen enough of these SoCs with "complex system of interacting components" to feel that a well thought out design that needs less static description of SoC/board/cpu level details would be beneficial.
Configurations pages are a thing of the past, nowadays they should at best be used for confirmation and sanity checks. Device trees are the future and have already improved and simplified hardware management a lot (specially on ARM).