Of course all these numbers are hypothetical, I have no idea what the actual Netflix numbers are, but aren't you assuming 100% profit margin ?

If you actually have a machine learning application that increases annual revenue by 10% and your initial annual revenue is $300M (like in the example) and your profit margin is 50% then (neglecting the $1M cost of the model because it's small and amortized over many years) your annual profits go from $150M to $180M which is a 20% increase. I don't think that is a number to yawn about.

On your last point I actually think the opposite is true. The larger a company's operations the more potential cost savings there are. If profit margins are slim, as they are in many industries, the effect on earnings of relatively small cost savings or revenue increases can be large indeed.