This article tries to conflate Liquid sidechain as something that is a part of Bitcoin.

It's not. It's a completely separate centralized ledger run by a federation of corporations. It's not open, permissionless, censorship-resistant or decentralized. It's an antithesis to Bitcoin.

It's just a bunch of companies piggypacking on the success of Bitcoin, and trying to build a financial system of Bitcoin on a digital ledger which they control.