If Starlink truly has a large financial potential for SpaceX, how come they are not launching a batch of these satellites every day?
What are the bottlenecks?
The answer, like many things in the business world, revolve around money and time. Building/developing a satellite, let alone a satellite assembly line capable of pumping out thousands of satellites, is not cheap and not quick. Even if you had an infinite budget, you can only hire so many engineers until you start seeing diminishing returns. SpaceX has made it clear that these first versions (both in "Starlink 0" and "Starlink 1") lack full capabilities, notably the inter-satellite laser links. As such, it's reasonable to assume that the technology isn't quite ready yet for SpaceX to commit to daily launches.
However, we can speculate and come up with many possible reasons:
Falcon 9 rockets are only available in limited supply. Even though they're reused, the seconds stages are not and it takes time to build those and refurbish pre-flown stage 1 boosters.
The launchpad/range isn't clear every day and SpaceX has to comply with weather, NASA, the FAA, and other regulatory agencies to get a launch window.
SpaceX may want to position the satellites into specific orbits which can only be reached by launching at specific times on specific days
SpaceX can only produce so many satellites per day
SpaceX wishes to test the current batch of satellites in orbit for a specified period of time before they commit to launching more satellites.
SpaceX does not have enough money to build more satellites and needs to drum up investors before they can continue R&D
Certain key technology (such as laser-links) don't work yet and SpaceX does not want to launch satellites which will be made redundant and outdated in a year or two