I strongly disagree with that statement.

Drivechains, and several earlier sidechains ideas, are not a scalability improvement, but merely enabling users to opt-in for another security model.

While obviously any future with wider adoption will need different technologies that have different trade-offs, and anyone is free to choose their security model, I don't think this particular one is interesting. In terms of validation cost to auditors, it is as bad as just a capacity increase on chain, while simultaneously adding the extra risk of miners being able to vote to steal your money.

Cheers,

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Pieter