That's used car salesman marketing speak.  The phrase means literally nothing.  Nobody in altcoins has improved on Bitcoin in any way except maybe anonymity purposes such as ring signatures and zk-snarks (monero and zcash).  I once thought some proof of stake systems like DPoS might have promise, but once you figure out the complete picture in how these systems works, you can walk away with no other conclusion than them being a step BACKWARDS compared to plain Bitcoin.

Although I would not recommend buying any altcoin such as Monero or Zcash until a few months after BTC halving or you will likely get financially raped.  The drawbacks of Zcash also kinda outweigh the pros of increased anonymity set over Monero to me.