Sure fossil fuel was necessary for some time but the only reason we kept going and still dependent on it despite the technological advancements and available alternatives is because of big corporations and some politicians who benefit from the industry (either financially or politically).
We could've stopped contributing to climate change some time ago but we choose not to. We can even do it today but we won't. Change has been painstakingly way slower than necessary because some rich people decided it was not worth the effort.
It's amazing what humans can achieve when we work together. We stopped using Chlorofluorocarbons and found viable alternatives when we decided it was worth the effort. We've eradicated smallpox ffs and we could've eradicated more diseases if we choose to.