Remember there is only one king of crypto market and that its bitcoin. Rest all alt coins are like followers of bitcoin. When bitcoin goes up alt coins goes up and vice verse. Alt coins are not in a position to move the market on there own.
Yeah, as per many veteran members of this forum, we do not need any altcoin investments as bitcoin itself got all the power of good returns for our money. I agree with them because as per them we do not need any diversification in this crypto space.
I have always said and I will always say this, the "phenom" that alts go up when btc goes down or btc goes up when alts go down has been broken before 2017 peak and never been the same since those days. But people seem to like to ignore that. Look at the price of top 10 coins in the past year, they all went up, they are all coins that got up together and when there was small corrections along the way they all went down together as well. This is why I think it is quite important to realize that there is nothing we could be doing that would change it. So long story short, we are doing one hell of a job by saying the opposite of what is going on in reality.
What's important to realise and a point that comes out to me from @bitgolden is that the two, BTC and Alts can't be decoupled. There will always be a relationship between the two with Bitcoin leading and Alts following (marginally). If you think your thoughts are drifted from this dogma then you need to go back to the fundamentals. We see this every time, BTC goes up so do alts and when the dump comes it all starts with BTC...