To defeat Bitcoin, an altcoin would require not just superior technology, but such vastly superior technology as to be an advance over Bitcoin comparable to the advance Bitcoin represents over fiat currency. Furthermore, a truly great innovation would much better serve people by being incorporated into future versions of Bitcoin rather than by requiring them to switch to something else
I think altcoin will have its own development direction instead of trying to replace Bitcoin because it's impossible. Altcoin has a huge problem that is strongly influenced by the bitcoin variation, when bitcoin changes the value, almost all of the remaining altcoin also change and that makes many investors uncomfortable despite investing in good altcoin.