Shitty companies did it like that back then - and shitty companies still don't properly utilize what easy tools they have available for controlled deployment nowayads. So nothing really changed, just that the amount of people (and with that, amount of morons) skyrocketed.
I had automated builds out of CVS with deployment to staging, and option to deploy to production after tests over 15 years ago.
The problem with renewables is the fluctuation. So you need something you can quickly spin up or down to compensate. Now you can do that with nuclear reactors to some extent - but they barely break even at current energy prices, and they keep having the same high cost while idle.
So a combination of grid storage and power plants with low cost when idle (like water) is the way to go now.