Yes, as you have noted, ALT's has some good oportunities. Some ALT's potential is nothing but huge. Only one major problem with ALT's ( as I see them):
There are 1293 ALT's on a list
If your selection becomes a winner - you become a winner. If not - just another loser.... :)
Just as with stocks, the smaller the market cap, the more gambling you are doing. Smaller caps require higher amount of due diligence and you're also often at an information disadvantage with other investors for these projects. As such, it's generally better to stay with those within top 50, delving only past that for cryptocurrencies that are either promising or have a ton of "shilling" support, as regardless of merit these types of cryptocurrencies tend to pump.
Top 50 to tough for me. After 6 yr in crypto space, I still advice a new commers "look no further then top-30" 😳
I like TenX, EOS, Metal, Ethereum and Litecoin.
But you can never win if you don't try to be a winner.