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.
Imagine having a money printer that prints an unlimited amount of dollars anytime you want. You don't have to do shit to earn it. Just enter the amount you want and press the print button. Voila! You are instantly rich. That's basically how garbage like dogecoin, ethereum, solana, XRP, fartcoin, pepecoin, clowncoin, etc. all work. They are just a digital recreation of the unlimited fiat money system but worse, with no discernible value beyond being a high-tech Ponzi scheme.
What are other differences?
You sounded like someone who hates anything related to altcoins. I do too but the fact remains, people love it because it's the fastest way for people to make money from the market and the truth remain not everyone will want to buy Bitcoin but fun fact, nobody hate Bitcoin and that's okay. You can hate altcoins but people who see what you don't see will eventually buy it and hold it, beside even as they are garbage people profit from it and all good.
The difference I was expecting, you never pointed it out, Bitcoin isn't altcoin and altcoins can't never be like Bitcoin, the level of trust in Bitcoin supercedes every other altcoins combine, Bitcoin is too trusted and that's why you see institutional guys all buying the ones they can see around but at the same time, the same altcoins you call garbage are other coins institutional investors has diversify their portfolio into and they are all doing good, what is good got goose is also good for the gander.
