My favorite phrase in coding is "9 women can't make a baby in a month, but 9 women can make 9 babies in 9 months".
Elon took over and fired so so so many talented engineers saying they were lazy, or incompetant, or whatever excuse he had when he really meant "they cost a lot". Now he's seeing the downside of that.
The phrase means you can't take a project and throw more people at it to make it go faster because there is institutional knowledge that needs to be learned first. You can't take a 9 month long project that 1 person is in the middle of and throw 8 more people at it and demand it gets done in a month, something Elon is really trying to push. Those 8 other people need time to onramp, to learn how the thing is being built, to learn how systems and subsystems all interact. In fact, usually this is a sign of a terrible leader because most of the time projects will slow down while you're trying to onramp all of those other people when at that point it would have just been faster to let the one person finish.
What you can do, as Facebook obviously did, is actually project plan. They said "we need 9 babies, what do you need to get that done?" and they replied "9 people and 9 months". and look how it paid off.
I hope Elon's twitter tanks because of his impulsive short sighted decisions that he thinks are "projects"