Polkadot may be considered equivalent to a set of independent chains (e.g., a set containing Ethereum, Ethereum Classic, Namecoin, and Bitcoin), except with important additions: pooled security and trust-free interchain translatability.
No coin can be an equivalent to bitcoin because they can never have the same potential, and you shouldn't use a centralized project with a decentralized one. Bitcoin has gained trust by the community and has great potentials which makes me think that it looks dumb to feel that Polkadot is worth seeing as an equivalent, when it doesn't have the potential to allow its price flow with bitcoin price movement at all time. I see Polkadot as an shitcoin whom the writer of that article is trying to hype.