You make bets on where the puck is going, not on where it currently is.
"How would a city with tens of thousands of HDDs transition to SSDs in the near future?"
It happens over time as products move to compete.
Client side machines matter less, the server will transition to ARM because performance and power is better on RISC. The military industrial complex relies on government cloud contracts with providers that will probably move to ARM on the server side.
It's not necessarily rewriting for Apple hardware, but people that care about future performance will have to move to similar RISC hardware to remain competitive.
"How would a city with tens of thousands of HDDs transition to SSDs in the near future?"
It happens over time as products move to compete.
Client side machines matter less, the server will transition to ARM because performance and power is better on RISC. The military industrial complex relies on government cloud contracts with providers that will probably move to ARM on the server side.
It's not necessarily rewriting for Apple hardware, but people that care about future performance will have to move to similar RISC hardware to remain competitive.