They put 2.05 MJ in and got 3.15 MJ out. The 300MJ comes from equipment inefficiency- remember this is a research facility to prove plasma physics and ignition itself, mainly designed for weapons research. The fact they got definite fusion at 1.53x input energy is not just breakeven, but net gain. This is the first time ever we've gotten net gain, in any fusion device. A lot of people in gov leadership thought fusion was impossible, the fact they can said they did it, despite 1980s era technology and a shoestring budget for decades, really says something. ICF is just one fusion technology, and probably not the best one, but fusion in general will probably see a massive budget increase worldwide now that it's been proven it can be done.

I fully expect a working fusion plant of some kind by 2030, assuming funding increases. Once we get them commercialized; coal, wind, solar and other power production will be obsolete for the most part. We can also use fusion heat to separate waste into it's base elements (you can recycle anything!), and help make any process needing a lot of thermal or electrical energy more efficient.