I agree for the most part. There are, however, two cases that come to mind for me as keyboards that did make a substantial difference:

1. Split-key keyboard. Got one when I was getting RSI issues in my wrists. That keyboard really did make a difference.

2. Butterfly keyboard on the Macbook. I hated it. My typing precision suffered. It's certainly subjective, but I was dropping my A's everywhere.

Other than that, my current mechanical keyboard has been mainly just a "it feels nice" thing, not a "I'm a better programmer because of it" thing.