The closer a spaceport is to the equator, the less fuel a rocket needs to launch from it. That's why Russia uses Baikonur, France uses Kourou (in French Guiana), and SpaceX uses the John F. Kennedy Space Center at Cape Canaveral in Florida. The only problem is the weather. It's not particularly stable in the equatorial zone.
And SpaceX has to take into account the state of the atmosphere in two places at once – the launch and the landing of the first stage. If the forecast is bad in at least one of them, the launch is postponed. The minimum postponement period is 5 days.
To create the declared constellation of 12,000 spacecraft, SpaceX needed to launch Falcon 9 every 5-6 days for three years. That is, to use almost all possible launch windows. And any postponement would push back the finish line by at least 1 week. And this marathon would have no end. After all, when the last satellites would join the constellation, the first ones would already be at the end of their planned operation period. Therefore, Elon Musk's statements about 12,000 and, even more so, about 40,000 spacecraft previously seemed too risky.
But if SpaceX has a launch vehicle capable of b2b email list delivering 400 satellites into orbit at once, that would change things dramatically. In this case, to complete the second phase (12,000 satellites), it would take “only” 28 launches. That sounds quite realistic.
Falcon 9 vs Starship comparison
The satellite goes to work
The second problem is reaching the working orbit. It is not enough to simply deliver the spacecraft to a given altitude. Each of them still has to take its place in the constellation. Therefore, as of September 2021, out of 1800 launched Starlink satellites, only 1420 are fully operational. Another approximately 253 devices are just “getting to the place of work”. This process can take up to several months.