Yeah but isn't it like, as the number of transactions increase the computing power must increase?

So if you had the world transacting on the blockchain ledger, it would take a crazy amount of computing power just to validate?

The computing power used for proof-of-work is not proportional to the number of transactions. Computationally, it's relatively cheap to verify the entire transaction history.

The real energy consumption comes from miners who use a crazy amount of computer power to secure the network. Bitcoin's transaction history is immutable because changing it would require an even crazier amount of computing power - too much for any malicious actor who tries to attack the network.

The amount of energy used is a feature, not a bug. There are no alternative designs known that could replace proof-of-work while keeping its security assurances, permissionless participation, fair distribution of coins, unforgeability, etc.

No, that's not how it works.

So why do they have farms in china for bitcoin mining?