Sooooo, there is nothing like a grand piano. I mean, nothing.
But, if you want to make sweet, sweet music, a keyboard is almost as good, and much smaller, and much cheaper, and doesn't need tuning, and can be used to make all kinds of other noises, and can be picked up and taken to other places.

What you said, that they said, about professional musicians is only sorta true. And gets less and less true as we don't put the input from the electric twanger onto tape, but into the computer.

So, from an analog, guitar peddle point of view, they are all analog circuits, like that one that makes it sound like a spring, is actually a spring the voltage is put through. There is nothing like it, but it. However, you can get 90% + the way there with a digital effects peddle. And, you get all kinds of other effects. And to the ordinary listener they can't tell the difference.

AND!!… for some artists, today, they like the digital versions because it reacts the same across the entire range, unlike many analog circuits. They aren't as fussy. (like you found out with voltage)

Now, for me, i bought a really nice electric piano. It had great key action, and really great recorded piano sounds. However, i (probably) would have been happier with one of those things that has a drum kit, and looping built in.