"Don't build skyscrapers, build townhouses!" "Don't have checkstops, people die in car accidents anyway, instead we need to think about road safety" "Why build a huge energy project when small towns won't directly benefit in the next 5 years"
You would assume that the considerations have been made because it's basically a massive engineering project, it hasn't been posted to hacker news for the purpose of gathering theoretical conjecture in step 1 of the planning process, and that's how massive engineering projects tend to work, along with other political effects that aren't necessarily logical reasoning experiments to begin with.
The other is that rich and middle class people in the developed world build their own little microgrids that can easily withstand primary grid outages with all the economic inefficiency that entails. Batteries are relatively scarce still and are far more equitably deployed to the grid writ large than only certain households.
But of course perfect is the enemy of good which is why people are arguing about this online.
Sounds like you are asking "don't spend 22 billion on infrastructure for yourself, donate 22 billion to build infra for someone else"
Hopefully they require a split of the power as part of the building conditions.
If the desert supplied energy to the whole continent, it would free up other resources (eg gas) to power other countries. It’s a little different to your river analogy.
What's the cost-benefit of installing heavy transmissions infrastructure for the desert? The shore? The sea and ocean? Everyone and everything who live there? How vulnerable is that infrastructure to natural and artificial disasters, and what costs do we bear to build resilience to those outcomes?
Aren't surrounding communities also in need of strong consistent power? Why not move the power less distance (far less materials, less power losses) and serve a different population?
The classic thought-terminating cliche of if we covered X% of the Sahara we could power the whole globe obviously ignores the act of moving that energy from one place to another, which is a huge endeavor, to say the least.
Your argument is basically of the flavor "why is California still in a drought while the Mississippi river rages?"