Hadron is used as a payment for running Machine Learning (ML) algorithms (which sums up to a bunch of calculations) on your device. When you mine using Hadron (via the website) you are doing ACTUAL calculations on your browser, for which you get rewarded Hadron coins.
Electroneum is meant to be a payment mechanism. Think of it like using your credit card to buy stuff online. When you are an Electroneum miner, you do not do any useful computations.
The bottom line is that the purpose of the tokens are totally different: Hadron is a token used as payment for AI/ML computations while Electroneum is a token that is meant as payment token.