The best value-for-effort upgrade to keyboards for coders would be to get a keyboard where each thumb can use two-three keys each (rather than just being able to use a single giant spacebar).

Stenography looks like 'high effort, high reward'.

Whereas, bringing keys like backspace, enter, esc, tab to within easy reach of the hands on home row is going to be a big increase in comfort (and I'd be surprised if it was slower).

I've used my Kinesis Advantage 2 for years and am inseparable. I'd like to swap to the Kinesis 360 but my current keyboard is just fine and it feels like a small upgrade