It is obviously a nonsense number for headlines IMO.
The entire Abu Dhabi Investment Authority sovereign wealth fund isn't even 1 trillion.
7 belt and road initiatives?
The simple explanation is that our media is mind numbing trash that has little to do with reality other than we wouldn't be talking about this if it wasn't for the fake 7 trillion dollar number.
It is basically like electric guitar vs classical guitar though.
Nylon has a very different touch and tension than steel.
You could start a student on electric or acoustic guitar that wants to learn classical guitar by why would you just not get them a classical guitar instead?
Same thing with piano to me. If you want to eventually learn to play some Chopin there is no reason you would not start with weighted keys.
The modern piano was also not even popular until the late 1700s.