Um, what do you think a blockchain runs on? The hardware is still there, the only difference is in what software is used on top.

Blockchains need power and internet, and run on hardware that needs maintenance and degrades over time.

> Someday, I believe blockchains will be more efficient and have fewer downsides than a Raspberry Pi.

A blockchain can never be more efficient than a computer because:

1. It runs on top of computers, and does extra stuff. Extra stuff inherently has costs.

2. Blockchains are based on very low trust systems and use trickery to overcome it. This has enormous costs.