"Free" in the sense of free extraction. Obviously you still need to pay for distribution, but the shale fields to this day are flaring off natural gas that they otherwise have no way to sell. That 50% drop in the 2010s is the shale boom.
Now that shale has calmed down and global demand has spiked, there's now a cost for the actual natural gas itself. A doubling of prices may seem like a lot, but historically the price is still well below average. Much like we've gotten used to free money over the last ten years, we've also gotten used to free gas.
That's not to say it isn't a problem, but we aren't in danger of running out of gas or any runaway price spikes.
Now that shale has calmed down and global demand has spiked, there's now a cost for the actual natural gas itself. A doubling of prices may seem like a lot, but historically the price is still well below average. Much like we've gotten used to free money over the last ten years, we've also gotten used to free gas.
That's not to say it isn't a problem, but we aren't in danger of running out of gas or any runaway price spikes.