You can add hydrogen to natural gas (using existing pipelines and storage), and so slowly replace that. No changes to existing infrastructure needed up to maybe 20% I think.
No one really knows how our existing natural gas infrastructure will cope with hydrogen
https://hydeploy.co.uk/app/uploads/2018/02/HYDEPLOY-FOURTH-O...
https://hydeploy.co.uk/app/uploads/2018/02/21935_CADENT_HYDE...
This isn't black-and-white. Leakage is a disadvantage, as it is for fossil fuels (natural gas, oil, coal,...). Other technologies have other problems: windmills kill birds and bats! Pumped storage kills fish! Dams cause methane leaks! It is important to quantify how much of a problem those disadvantages really are.
https://theconversation.com/dont-rush-into-a-hydrogen-econom...
https://agage.mit.edu/publications/global-environmental-impa...
more skeptically, given that green hydrogen remains a pipe dream, it's both a useful delaying tactic for switching to electricity and furthering investment in fossil fuels, which must stay in the ground if we are to have any hope of staying below 1.5c.
https://www.carbonbrief.org/new-fossil-fuels-incompatible-wi...
Yes there are many delaying tactic for switching to electricity (the promise of "synthetic fuel" for example, to power existing gas cars). But using hydrogen to replace fossil fuels is needed anyway, for example for ammonia production and steel manufacturing. So I don't understand why you think hydrogen will delay the switch to electricity.