1. The fuel is free to cheap, depending on the fuel; and
2. Stars can do it so surely we can.
So let's consider a mythical plant that costs $30B to build, has a lifetime of 30 years, costs $3B/year in maintenance and produces 1000MW of power. And the fuel. is free. Is the electricty free? Not even close. That's ~8.8GWh per year. No plant runs at full capacity 24x7 so let's call it 4TWh. That's about $1/kWh. That's ludicrously uneconomical. Of course you can throw in vastly different numbers and vastly different results but the main point is that fuel cost is a non-issue.
And as the article points out, in a D-T reactor, you still need to produce tritium because it's basically not naturally occurring in a way that can be gathered. That means a fission breeder reactor. That fuel isn't free.
Second, "the Sun does it" misses the point. As the article correctly points out, damage from neutrons ("neutron embrittlement") is a huge problem. Beyond that, it's a huge problem because every high-speed electron that escapes the plasma is energy loss from the system.
Stars use gravity for containment.