If Germany were to rely just on solar and wind, the low capacity factor would likely require massive grid storage. The only large scale grid storage we have at this point is pumped hydro and that isn't scalable. For example, one estimate is that for Germany to rely only on solar and wind would require about 6,000 pumped storage plants which is literally 183 times their current capacity.
If making more grid storage was cheap and easy, we would have built it decades ago. This is why Germany is still burning so much coal.
What happens when the sun does sign?
What happens when the wind doesnt blow?
What happens when power demand rises and drops throughout the day?
Solar and wind cannot support a base load period. Battery tech is great and believe me it's cool but lithium ion batteries have been in place since the 70s and the chemistry hasn't improved.
Instead of sitting on our hands with a thumb up the bum, waiting for breakthroughs that never come, we have solutions today that work and should be leveraged before those gains in chemical engineering and material science happen.
