Another reason we haven't had those blackouts is that electrical efficiency is increasing, even as we increase demand. For example imagine all the CRT screens, street lights, and incandescent bulbs that were all replaced with LCDs.
You can have a demand for more lumens of lighting power... but if you previously used incandescent bulbs and now go for LED, you can expend less electrical energy than you did with the old bulbs.
Similarly, an induction motor controlled by a variable frequency drive can use much less energy by varying its speed instead of using a fixed speed motor starter. VFDs typically get signals from building automation or process control systems and adjust the motor speed accordingly. An arbitrary example would be a fan running at 50% speed generating 50% airflow but using only 25% of the electricity needed to run at 100%.
https://www.energy.gov/eere/amo/articles/adjustable-speed-dr...