Once you realize the byproducts of oil and how essential some are and the fact that rich countries aren’t going to change their way of life and the fact that developing countries will industrialize in the same way western countries have and will start to produce similar environmental emissions things look pretty bleak in terms of that average temperature rise.
You’re right it’s not a fact. But I would say large percentage of developing nations aren’t pursuing such options because it’s easier to use things like coal. If you take a look at the new coal plants under construction as the moment, the top 15 are from developing countries. https://www.carbonbrief.org/guest-post-just-15-countries-account-for-98-of-new-coal-power-development/
China and India account for 3 billion people alone and they’re still building new coal plants to account for their growing energy needs despite using renewable energy.