Power has two big costs: generation and distribution. Once rooftop solar power is below the cost of distribution it doesn't matter how much it costs to generate power; rooftop solar is always going to be cheaper.
That milestone has been hit in some places Australia already.
If the system still depends on distribution, someone has to pay for it.
It may be that rooftop solar users will be asked to pay more for that distribution than they think is reasonable.
I’m sure not excited about my grid operator proposing a $50/month minimum for electricity, it makes my panels seem worthless. But there is logic; I was being subsidized by net metering. And in future I may have to pay a cost closer to the true cost of access to the stability of the grid.
That milestone has been hit in some places Australia already.