To me the biggest difference is how bitcoins are created. It takes a great deal of investment in time, effort, money and energy just to mine and produce a single bitcoin.
Unlike altcoins, you can't just print a bitcoin out of thin air whenever you want. Any idiot with a PC can create a new crypto altcoin and print an unlimited or nearly unlimited supply for himself to dump onto the market, whenever he wants. But that's not how bitcoin works.
Well, this are also part of the vital points we can consider over the use of bitcoin, but you can come to think of it this way, from the PoW and PoS, you will discover a massive difference and know why the PoW is more preferred, you can also consider the bitcoin nodes, decentralized and how the bitcoin network transactions fees works compared not other altcoins, with all these, you're going into discover on a perfect way to approach the use of crypto with Bitcoin and any other were just an attempt to copy after it.