I think that Bitcoin will alway be above all other cryptocurrencies. Bitcoin is first cryptocurrency and that gives it a lot. It broke the ice and showed people what cryptocurrency could be or become. Also if it was not the best, it wouldn't have the highest price. Maybe in time it will lose to some other or new crypto, but for now its first.
The best part about bitcoin is that even after having a small market cap, facing china's ban and constant volatility, it was able to hold and increase value in such a short span. Cryptocurrencies as a whole is developing as well. It didn't have a downfall as such it's just become more popular.
Bitcoin is very resilient from such attacks, not even China announcement about bitcoin and the recent well orchestrated attack by the people behind Bitcoin Cash prevents it from going up again. Bitcoin has already captured the hearts of many investors and wouldn't let a single aggressive action against bitcoin overcome all their money in the ecosystem. Just by looking at the current price, bitcoin is becoming more popular. It never lost its dominance, just a some power grab but eventually bitcoin won. Let's see what the next challenge is, but rest assured that bitcoin will took it everything in stride.