It takes time for new technology like the blockchain or cryptocurrency to gain popular support and adoption. Bitcoin being the first cryptocurrency has the time-advantage over all other coins in a way that can't be overcome. It will take another decade or so from now for any crypto made today to gain the same acceptance that bitcoin enjoys today, but by then bitcoin would have had another decade.
We are still very early in the era of crypto and bitcoin has the first mover advantage, something that can't be understated.
Plenty of new coins are made so as to try to solve "problems" with bitcoin, however cryptocurrency is adaptable and bitcoin layer 2 solutions solve many of the problems that others have tried to solve by creating new coins, since bitcoin is not set in stone and given the adaptability provided by layer solutions, it's difficult to imagine bitcoin would become de-crowned as the kind of crypto, at least not anytime soon.