As mentioned in the other follow-up: Even using gas turbines + heat pumps would reduce the required amount of gas due to using environmental energy.

And then there's wind (as mentioned: we just broke records. In winter. At night.), and water (to some minor degree). And theoretically a comeback of nuclear (won't happen). Or hydrogen storage. Or fusion, or whatever. The good thing about electricity is that it doesn't care where it comes from, and there are many different kinds of sources.

On the other hand: Natural gas boilers require natural gas, and so far we don't have methods to synthesize it from electricity - or anything else - at scale. The main argument in their favor is that they're installed: a pretty important argument though.