The biggest risk and disadvantage is that you will miss out on potential btc and eth runs and with experience i have learnt that staying in btc and eth remains to be the best strategy for me in the crypto investment sphere.
Completely agree. I've modified my investment strategy to just holding BTC and ETH as well. Simple to follow with a lot of upside potential long term.
I do agree with this disposition in terms of crypto investments. If you are a type of person that can't follow thru all the coins that you are holding. Better convert it to btc or eth, if you have the chance of selling those other altcoins in the market. At least even if you forgot to check on a specific coin, you already have your btc or eth in your holdings.
By the way, the OP already summarized what would happen with your altcoins if you will hold them in long-term basis. And for me, those scenarios turned to be true to more than half of the altcoins ever existed.