I'm not really qualified to tell you exactly what it does, but I did pay a little attention to it for a little while when I was learning Bitcoin. almost every improvement an altcoin offers, can be solved with a layer2/3 solution at the expense of everything that Bitcoin stands for.
ie: decentralized, immutable, uncensoreable, and finite.
Read my avove reply. Only the blockchain is the same. The purpose, phylosophy is different. Many "altcoins" are not coins rather than tokens. E.g. Ethereumnis a completely different layer 1 infrastructure with the smart contracts built in the network. ADA is mainly for agriculture, Stellar Lumems is mainly for transportation (see IBM-Maersk solution to track all containers), Ripple is to replace SWIFT, Gaming tokens for gamers (to buy gadgets, ammo, armor, other "NFT"'s), and so on. Of course the first memecoins were just for fun (Doge) or pranking -/as a definitive Ponzi scheme prank, named Ponzicoin.
And there are/were scams e.g. the former Onecoin.
