You also need sensible storage options for the renewables. It doesn't have to be just batteries. Why not produce hydrogen or better methane from excess renewables? You could also continue to use the gas infrastructure for that. It is technically possible! What it costs is another question. Today, wind and solar power are sometimes curtailed.
And about biogas: a very significant part of the land is used to grow animal feed. That will also decrease with declining meat consumption. You can't grow wheat year in, year out, which is by far the most important bread grain. Instead of animal feed, energy crops and biomass for biogas plants could be grown (of course adapted to the region, specifically what). Naturally, there must still be a net energy gain compared to production. As far as I understand, biogas has also been politically deliberately restricted. There is certainly still potential there.
Conclusion: Anyone who does not believe at all that a 50% increase in the CO2 content of the atmosphere by humans has influenced the climate will not be convinced. They believe we can just keep burning fossil fuels forever and everything will be fine.
And for everyone else, all one can say is: let’s do something. Renewables are by no means superfluous. Quite the opposite! Technically everything that is needed already exists today, without nuclear power, by the way. We just have to want it and implement it!
And the eternal whining "but what’s the point, others aren’t joining in" — someone has to start! Michael Jackson already knew: "I'm starting with the man in the mirror..." Recently there was an encouraging article in a magazine that you might also want to hang on the wall. Five things that can give courage that things are indeed progressing elsewhere in the world. We are by no means as alone in Germany as it is always portrayed.