I didn't bother reading that blog (I don't like almost empty topics which forces forum members to click an external link) but to answer the question which one to choose, it probably depends on the type of NFT.
Those platforms on Ethereum are still more popular and have more user base when it comes to arts. If I want to sell an Ape smoking some shit, I'd probably choose Opensea.
If I want to invest in NFT gaming, I'd most likely choose a project on Polkadot because............high ethereum transaction fees.
that's my point to read the blog itself and who's is presenting !! the blog belong to xp network who has a multichain bridge platform and you can move NFT's too al Connected blockchain's like Ethereum/Fantom/Elrond/BSC/Polygon/xDai/Avalanche and more soon that way you can save money and costs small fees
![Kiss](https://bitcointalk.org/Smileys/default/kiss.gif)
next time please bother yourself by reading the blog or website everything has a reason