Which Altcoin is next to Bitcoin and is being accepted worldwide?
For me it is eth. You can convert eth to btc so we can use it. For me ETH and Bitcoin Cash is next to Bitcoin. I also think that it is our job to convert our ETH and Bitcoin Cash or any altcoins that we have before we use it.
I do agree ETH is next to bitcoin even in the market it does , ETHEREUM is also very useful you cannot convert any alternate coins if you do not have ETHEREUM because it is the fuel of every transactions you will do.