Mhmm, think of it like a large house. You have a bunch of circuit breakers. If you pop the wrong one you’re suddenly in the basement in the dark trying to figure out what pop’ed. Power grids work the same way. If something pops, you need to go out and figure out what popped where; and then look into what needs to be fixed, if it’s just a bigger tripped circuit, if it’s an old school fuse or if it’s something more complicated like a new line that needs to be run.
if the power outage is large, turning on too many different power connections at the same time can also place a lot of stress on the grid, turning on sections at a time can prevent this. think of all the ac units, refrigerators, etc that’ll be running at full power if the outage lasted a long time