Here lies the problem: you live in the present, I live in the future. And right now, I don't see any reason why that can't be fixed in the future.
You said blockchains are more practical, in the present tense. The evidence strongly suggests that's not true. And there are plenty of reasons to think they will continue to be impractical in the future.
The popularity of centralised exchanges vis-a-vis blockchain wallets suggests the opposite is true.