Vals AI CEO Rayan Krishnan on why defensible evals are critical for enterprises' survival: "The labs side of it is very clear. If you're raising lots of money, investing heavily in building models, it's essential for you to show why your model is getting better and why the customer should pay a premium for them." "But what I think is still underappreciated is, on the enterprise side, this is turning out to be existential as well." "We're in this world where it is still very unclear what ROI…