Bitcoin is always better than altcoins, in my opinion. Its having higher price and more stability, despite its price volatility (which is common with altcoins too). But you can invest some of your capital in the highly traded altcoins
With the price of bitcoin so high,it is not the best form of investment if you are looking for a good profit,there are coins with low valuation and good projects which can give you a higher yield than bitcoin,so make sure you find a better alt coin or project and invest in it rather than in bitcoin and that is my opinion.
At this point where the price of bitcoin is high, it is not advisable for us to invest in it and if we do, earning profit might take a long time. But there are people who thinks that investing in bitcoin now might be a good choice since the price of bitcoin will probably continue to climb up. Yes there are altcoins that can be considered for investment but of course one must study first and know if the coin shows possible growth or gain in the future. Choosing a coin for investment is a risk also and if you are not sure about the coin try to look at its history and see if people demands it over time.