The solution mix needs to be tailored the location.

Non-tropical equatorial countries don't have meaningful seasonality, so they don't need seasonal storage.

For countries far north of the equator, it's more challenging, but there are multiple tools to address this, including: over-building so you have enough in winter, using wind which is seasonally negatively correlated with solar, importing power over HVDC, and diversifying wind spatially to reduce correlations which drop more than linearly in distance.

For small countries very far away from the equator that have highly variable insolation and limited geography to decorrelate, nuclear may be better. But it cannot be asserted a priori without a simulation study tailored to the specifics of that location. When I said that nuclear is bad, I am talking in generalities about the common case (United States) at current market prices.

The paper that you linked is old, we are dealing with exponential change in the price of storage and solar.