> The moat of hardware effects processors has just vanished.

There was never one to begin with. With a sufficiently good quality generator and a digital oscilloscope one could reverse engineer any kind of DSP - including harmonizers.

The real moat is the same as in every business - customer service, durability, warranty - things like that.

If someone vibecoded a clone of Valve's Steam nothing would change, because the system itself is not the thing that makes their business so valuable.