Back in the day
When I was a lad at a school in Oxfordshire (*) in the eighties we went on a field trip to the local fusion reactor experiment. I seem to recall that they talked about orders of magnitude out from sustainable fusion rather than a factor of two. I remember seeing a graph of progress with a logarithmic Y axis and a fair way to go on the X axis.
They talked about "50 years away" (or was it 25 - that X axis was hard to interpret!) and I note that reasonably current articles in New Scientist still mention similar timescales. It will happen one day but it is rather expensive and rather hard to get politicians to sign off the vast sums needed for a very, very long slog.
(*) WTF Google - that's how its spelt - what's with the squiggly underscore?