The article is a bit skimpy on details and the curves really simplistic – well it's log scale – but the conclusion I can see, even if fusion power plants would work, they probably won't be cost effective soon.

Fusion power unlikely to become competitive - Nature Energy
While nuclear fusion power is often hailed as a future source of abundant, clean energy, current dominant fusion designs, magnetic and laser inertial, are unlikely to become competitive due to their expected low experience rates. Accordingly, policymakers should not rely on, or fund, fusion power as a core pillar of future clean energy systems unless designs with different characteristics are developed.