Environmental issues aside, gas is also a pain for installation. Solid pipes are more difficult to route, and leaks are, of course, dangerous. Electricity is dangerous, but it is easier to contain. It doesn’t leak into the air, and because it’s a closed loop, we can measure if it isn’t all returning and shut it off (RCD/GFCI). It also has flexible cables. The downside is that, heat pumps require more maintenance. They’re a vaguely complicated mechanical system, as many fluid systems are.