I agree with you that altcoins are not for newbies because of the risks they bring, but it should not be denied that altcoins are also a very good way to make profits if we know how. ...
If there are doubts about which coin to invest in, you can see where large companies such as Grayscale invest. Their open-to-all portfolio shows that big business invests not only in bitcoin -
https://grayscale.com/products/ But with all the variety of different coins in the portfolio, the largest percentage is allocated to bitcoin.
agreed with this statement, these large companies are investing with proper research, so if someone are doubtful in regards of their portfolio holdings then they should seek inspiration from these large companies portfolio and see how much they allocated in certain coin and how they diversify.
I'd say it's always good to have these large companies as a reference even though most of the time their investments only suited for long term.