Your 80/20 assumption is flawed for a couple of reasons. Firstly, it only applies if you are picking projects at random. Secondly, much more than 80% of altcoins are complete trash and will be worth nothing long-term.

I own more than 3 coins. I am completely happy with all the coins I own because I have spent time reading their whitepapers, roadmaps, githubs, development, etc. and not just blindly listening to shills on here/reddit/twitter/4chan/anywhere who say "good project" about whatever bags they happen to be holding.