Bitcoin is still the best coin ever and nothing shakes the faith of bitcoin because it's the leading cryptocurrency with the highest market cap. Some altcoins are being pumped and that pump wouldn't last. I don't see any altcoin that can do well in future compared to the milestone that bitcoin have achieved.

If bitcoin price is stagnant, it's only a temporary thing and the price will surely recover and maintain its nature. Bitcoin price movement is what controls those altcoins and don't think that a time will come for altcoins to do better than bitcoin because the adoption rate is increasing exponentially overtime. Even the shitcoins devs are also buying bitcoin.