Which altcoins from the last few years where there was a lot of positive talk about it has failed? And by failed, it means either it has went to 0 or it could be worth very little. Like it could been 50 dollars at one point and now 0.50.
I know one name which is EOS. When this coin was launched many said that this project would be an ethereum killer. but today we see EOS is not even one of the choices of the project developers. I see no one is using their network. and the price of EOS has fallen greatly. maybe these coins have lost 90% since their last ATH. in 2018-2019 eos is still in the top 10 largest marketcap. but right now EOS is way below.