can you give me a like, more clear practical example of a good use of blockchain?

Do you see how all the answers are generic, tend to be long and read like a sales pitch? That's because the actual answer is: no, there is no practical legal application that isn't better solved with conventional tech.

The only application that is successfully used in practice is paying for organized crime: buying goods and services on the dark web and paying for extortion like ransomware attacks.