I have done a long, deep and intensive research over days and weeks just in case to diversify a small part of my investments into potential interesting projects/coins. Beside ETH (which wont make any really big gains any more) and XMR I only could find IOTA interesting, while still very experimental. Everything else is damn useless bullshit I would never put a cent in. Even BTC is a bad joke from fork to fork it is becoming just an expensive, overvalued and slow altcoin with no special features.
Simply happy to be invested in XMR.
I did the same research and came to exactly the same conclusion. BTC, XMR, ETH and IOTA are the only ones that are interesting and XMR and IOTA are the only two that I currently have skin in.
Yes, I think the problem with most newbie investors is that they try to find the next X100 and buy any kind of coin which makes this promise. While doing that, they miss out the next X10 or X30 and that is what I see in IOTA and XMR. From the 4 strong and healthy projects (although BTC may not be healthy any more) which are BTC, ETH, XMR and IOTA, only the last 2 have a small market cap of 1 billion USD.
Other top 10 coins like LTC, NEM, XRP, DASH etc. are a joke.
I only like to put my money into quality stuff, where I can hodl even through lows with no problems because I know the value will come back again.