...what I have understood is that bitcoin isn't a good invention, but it's a good innovation...
The blockchain man, it is a fucking
invention, the world had to wait 30 years for this one after public key cryptography was invented.
While I agree, that blockchain is the part that could be classified as an invention the most. Then I still have to say that I see it more as an innovation, because it is built on already created inventions in cryptography. I think that blockchain is a great innovation, but I also think that it will be as great of an innovation in the future as iPhone1 is right now.
I partly agree, because the blockchain (the distributed blockchain, really) was inspired by some proof of work testing as an email spam antimeasure. But following crypto developments from the sideline for many years, reading the bitcoin whitepaper was a revelation.