No matter how many coins will launch in the market, the Bitcoin will still dominating the crypto space, no matter how hard the dev tries, they will just behind the Bitcoin, it is the king of crypto and nothing could beat or replace on its place.
There is no guarantee that Bitcoin will never be replaced by a technologically better alternative. As the case with all the technological innovations, Bitcoin also will be eventually replaced by something else. However, right now there is no such alternative in existence, which has the capability to overtake Bitcoin. There are technologically advanced cryptocurrencies available, but their basic concept remains same as that of BTC.
If a developer wants his coin to replace Bitcoin, then he should be ready to try a fundamentally different approach. He should be able to come up with an alternative to Blockchain. As of now, almost all the cryptocurrencies use some form of a Blockchain to store the transactions. And since it was originally a concept invented by Satoshi, Bitcoin remains on the top as the "original" cryptocurrency. It is possible to replace Blockchain with a better concept.
It would be kind of hard now for bitcoin to be replaced by any technology, it would have been easy at the early stage before bitcoin technology became this popular, and if you can see that it has gone beyond just individual and it is already creeping into the government system, and anything that is beginning to involve government would be difficult to be replaced which is why we are still finding it very difficult for bitcoin to really go high as much as it ought to have gone because the government are still holding on tight to that fiat that they have been used to for year and which they have full control over.
If bitcoin is still facing it hard with them, then no matter how good the new technology is, it may really not get that recognition enough to beat bitcoin.