Simulations, not simulated users
I really don’t like the framing of “synthetic users” for the new wave of agents simulating user feedback, grounded in actual user data or not.
I much prefer and have been advocating calling them “simulations,” which is much more accurate to what is actually happening, is a well established approach to prediction in the absence of direct data, and avoids the pitfalls of putting them so ontologically close to research with humans.