You are wrong. Lightning works by using smart contract logic. For Bitcoin in particular, that involves using Bitcoin scripting using real Bitcoin transactions.

That blogpost is basically describing lightning. Lightning Network has explicitly described instant cross-chain swaps privately, and publicly for many months.

Yes, and on a platform that allows for arbitrary logic, like a Turing-complete blockchain, or just a regular server, Lightning-like transactions are trivial. They can be described in minutes, and implemented in weeks. Due to the limitations of Bitcoin script, Lightning takes 60 pages to describe and is still not implemented. It's a revolutionary concept, hobbled by an antiquated platform.