Soon isn't a thing that happens with power grids in any normal sense. The big capex in creation means that you need big differences in cost to justify an early shutdown. You also have to the new working before turning off the old, contrary to political preferences to destroy the old and then try to make the new work. Plant modifications are smaller in cost usually - so swapping a coal plant to burn natural gas because fracking made it cheaper (not without its own costs) is a small step.
If wind and solar remain cheapest per MW*hr they will grow to saturation.
What happens when the wind doesn't blow and the sun doesn't shine? Where does the energy come from? Today, when that happens, the energy comes from natural gas and coal during these times when European renewables are unable to generate much power. All this expectation that we will be on renewables by X date hinges upon developments in battery storage capabilities by X date that have yet to materialize. On the other hand, we have nuclear energy which could have solved this problem 70 years ago.
Not too mention the problems with various batteries such as longevity, capacity, location and safety. Applies to gravity, ion and gas energy storage unfortunately, not as easy as lower and raise the control rods in a predictable manner unlike our eastern European friends.
If wind and solar remain cheapest per MW*hr they will grow to saturation.