I wonder about the total energy cost of apps like Teams, Slack, Discord, etc... Hundreds of millions of users, an app running constantly in the background. I wouldn't be surprised if the global power consumption on the clients side reached the gigawatt. Add the increased wear on the components, the cost of hardware upgrades, etc...
All that to avoid hiring a few developers to make optimized native clients on the most popular platforms. Popular apps and websites should lose or get carbon credits on optimization. What is negligible for a small project becomes important when millions of users get involved, and especially background apps.
If we go by Microsofts 2020 account of 1 billion devices running Windows 10 [0], and assume all those are running some kind of electron app (or multiple?) you easily get your gigawatt by just saving 1 watt across each device (on average). I suspect you'd probably go higher than 1 gigawatt, but I'm not sure as far as making another order of magnitude. I also think the noisy fan on my notebook begs to differ and maybe the 10 GW mark could be doable...
[0] https://news.microsoft.com/apac/2020/03/17/windows-10-poweri...