The increases in the price of gas, in particular, are caused almost entirely by the rise in the wholesale price rather than profiteering. I agree that the energy companies and the distribution network are inherently monopolistic and should therefore be nationalised (just like the water companies and the rail companies). However, if the government did this alone and passed all profits back to consumers as reduced prices, it’d have much less of an impact than most would imagine.
The sanctions against oil and gas producing countries are the single biggest cause of this crisis. It’s all well and good talking about energy security, but even if the government did enact policy (big if) then it would take years for any noticeable relief in prices. Western governments could lift sanctions on Iran and Venezuela tomorrow. That’d go some way to addressing supply shortages, although it might be severely limited if Saudi Arabia follows through on its threat to cut production. Iran and Venezuela combined produce about half as much gas as Russia.
The government could do what France are doing, but it’s really only deferring the problem until later. The French will pay one way or another, but I suppose they’ll at least not freeze this winter.