It's a hard question. I thought about it myself for a while. I am not good at technical stuff, but it also occurred to me that many coins are indeed better than Bitcoin. Simply because they took the best it had and had an opportunity to fix what was wrong with it or simply offer some improvements. However, it seems to me that the problem with transaction fees and speed is ultimately the problem of blockchain itself. The only thing you can do is make it somewhat better, increase the capacity, so to speak. But the main problem lies deep within: whatever you do, the more transactions there are, the more time and money it takes to confirm them. And you know what? We actually even have cryptos that don't have this disadvantage. They are built on DAG, not Blockchain. DAG has a different principle of working, and with it the more transactions there are, the faster they get confirmed. The problem with DAG, though, is that it's very hard to ensure proper and not too centralized work of the coin before it gets a big and active community. Plus it's buggy, or so it seems.
But why Bitcoin is still #1? Some even make this point, that it's clearly not the best, and time will come when cryptos will be our future, but Bitcoin will be left behind, like with the .com boom.
I think that since Bitcoin was the first successful crypto, it also became the most famous one and the most innovative one in comparison with fiat, so this popularity and respect of innovation pushed it forward and might even push it forever.