It is unrealistic to expect the world to 100% run on renewable energy. The infrastructure required for a complete transition is expensive and time consuming to implement. Renewable energy sources like solar & wind are intermittent & dependent on weather conditions which leads to fluctuations in supply. The storage & distribution of renewable energy on a large scale pose significant challenges. Some industries & regions heavily rely on non renewable sources like fossil fuels for their energy needs. Achieving a 100% renewable energy world would require substantial technological advancements, policy changes & global cooperation.
I think it's still possible, but it will take time for sure.
but along the way we can still focus on diversifying energy sources and one of them could be green hydrogen.
industry revolution toward the greener path and reducing carbon footprint will be an extensive and cost hungry effort but I think the fact that so many institutions still pushing for green energy is a good thing.
we're still too early to say that it's unrealistic, maybe within next decade we might see some significant technology advancement that allows the use of renewable energy and also boost the production of renewable energy, after all technology developing so fast.