Any cryptomining experts? Help me understand something

So I've looked into blockchain technology, if you haven't, look it up. Some are saying this will be the next tech revolution after the Internet. Now I get why Jensen Huang is acknowledging it as growth driver and I bet AMD is too, but not publicly because they're more conservative.

But as you probably know there are more efficient ways of mining than GPUs, dedicated ASIC machines: https://www.bitcoinmining.com/bitcoin-mining-hardware/

I understand why gamers who do mining on the side would use their GPUs since they already have the hardware, but for intensive miners (I even saw cloud mining farms using tens of thousands of GPUs), why would they use GPUs instead of those ASIC machines? I must be missing something.