That wildly overstates how far off we are. To take the most conservative example, tokamaks have very well-known scaling laws and based on those, CFS is generally expected to exceed breakeven with SPARC and get to practical power levels with ARC, over the next several years.

I'm happy to find myself corrected but I'm somewhat skeptical.

What is the limit on the scaling then? If we can scale up tokamaks, why aren't we right now building 10GW plants? 100GW plants?

The scaling constraints on other forms of power generation are well understood but the scaling is limited by safety/regulation and by logistics.

> over the next several years.

More like decades. The earliest time any planned fusion reactor will make net electrical output -- but not yet an economically useful amount -- is the mid 2030s, a decade from now.

Commercially relevant amounts of electrical generation is uncertain, but most plans start around 2045 and then would take decades to replace fossil fuel plants at scale.

There's a big difference between "it will be decades before we've replaced fossil plants at scale" and "we won't have net power until we invent magical new technologies that we have no clue about today."