Solar and wind most certainly do disrupt baseload, and they can do that even if they are not themselves providing a constant output of power. All they have to do is drive the price of power down often enough to ruin the economics of the expensive baseload plants, which depend on there being sufficiently high average prices.

This is simply false. First, "base load" powerplants are actually the most troublesome, because they don't adjust for load and predicting base load is actually hard (except when you just use a very small fraction of overall load). Second if you have a large grid (like the US) that is connected (and modern,) you could run the whole grid of variable loads like wind. This would require investment into the grid which nobody seems to want to do. However the technology is there