I'm not entirely sure what you're rebutting, and I certainly don't know what "equivalence" I made which was "false". I just compared what you can get from a digital piano against what you can get from an acoustic piano.

If we set a budget to $1k, then sure, I agree that you'll have a hard time finding a decent acoustic. I'm not sure, though, why we should assume $1k is an average, and even if it is, why we ought to use that as a benchmark for characterizing acoustic pianos.

Buying a good quality grand piano is affordable to middle-class families. It's not unlike buying a car: you can get them new or used, financed or paid in cash. So somebody, who at least has middle-class financial means, who is serious about learning piano, absolutely has the opportunity to get an instrument they can connect with (in the specific sense I described).

It's not cheap, and to most families it certainly couldn't/wouldn't be a frivolous purchase. But that's just how it is with a decent acoustic instruments. Digital pianos are much more affordable and offer a lot of practical benefits, but they're still significantly different from an acoustic piano in every dimension.

> Buying a good quality grand piano is affordable to middle-class families

I don't know if even having the space for it is affordable to middle-class families.

I don't know what kind of income level are you talking about when you say "middle class family". Afaik, most middle-class families can't afford to spend money on a good quality grand piano. I would be even surprised if they even had enough money to maintain it or if they had enough space for it

It's gonna be hard to tell some parents why they should dump over $1k on some fancy piano when they can spend way less than that on a digital piano.