You aren't going to find any one category of thing that uses a "significant" fraction of total electrical energy or fossil fuel. Dismissing efforts because of that won't lead to meaningful betterment.
The 2% use for IT is insignificant in contrast to the 28% used for transport which is the most significant.
If you truly want meaningful betterment you need metrics to focus your time and effort where it will have the most impact. If you spend all your time focusing on the most insignificant thing you can make massive progress in that thing and no progress toward meaningful betterment.
Around 90% of energy production of the world comes from coal, oil and gas, with each around 30% contribution. Simply changing our energy sources will lead to the most meaningful betterment.
If you truly want meaningful betterment you need metrics to focus your time and effort where it will have the most impact. If you spend all your time focusing on the most insignificant thing you can make massive progress in that thing and no progress toward meaningful betterment.
Focus is very important.
https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emis....