Has the Cross-Chain Trend Changed in 2021? BSC, Polkadot, and Layer2 Launch "Three Kingdoms Competition"

At the beginning of 2021, blockchain development entered the cross-chain wave, which was both reasonable and unexpected. It's reasonable because everyone already knew that cross-chain would be one of the hottest trends this year. Cosmos IBC protocol was officially announced in February, and Polkadot KSM parachain slot auctions are just around the corner. These two cross-chain stars are joining hands to bring blockchain into the "year of cross-chain". It's unexpected because BSC and Heco, along with many other high-speed public chains, have been "forced to rise" under the situation where Ethereum Gas fees remain high every day.