One of the saddest tales of hardship following Storm Arwen was told by a woman lamenting that, if they hadn't just changed their old oil heating system for a new air source heat pump-based one, the loss of power wouldn't have deprived them of heat as well as electricity.
Something rather similar happened locally, when a district heating system failed over this last, perishing cold weekend; see https://www.hackneycitizen.co.uk/2021/11/30/shoreditch-pipe-leak-450-residents-without-heating/ .
That reminded me just how useful it is to have both gas and electricity, as when my new gas boiler broke down just after I moved house at the end of November. At least I still had an immersion heater to produce hot bathwater, after having to keep 'warm' getting grubby with endless furniture shifting, cleaning and unpacking of boxes.
If we all go all-electric, we put ourselves at the mercy of a breakdown in our only source of power. So I'm hoping that pure hydrogen-fuelled boilers become practical in London by the time that my current gas boiler needs replacing. I don't want to lose the alternative source of power, in case something goes wrong in future - as it invariably will do, sooner or later.