I'm not entirely convinced about the rationale for hydrogen, but I'll play devil's advocate. If you burn the CH4 at the place of extraction, then you need a way to transport the electricity. This is a hard problem. You can instead ship the natural gas via pipes (or LNG) to some other place, close to the consumer, where it will be burned in a power plant. For this option, there will be leaks proportional to the distance the gas is shipped. A pipeline 100km long will leak 10 times more than a pipeline 10km long. When the famed analysis that claimed 3.5% average CH4 leakage came out, they simply did not consider the length of the pipe. If you instead immediately convert the CH4 into H2, and ship that via pipes, then you have no reason to have CH4 leaks beyond a tiny amount associated with the extraction itself (which would be there even if you decide to convert the gas into electricity on the spot). So, all in all, there's a case to be made that the conversion of CH4 into H2 would result in great reductions in overall greenhouse gas emissions.