Yes, startups and small companies can get things done more quickly. There's many reasons, but mainly I think it's that the system isn't very complex yet. Your first line of code has -nothing- that it can wreck. Your first system can't interfere with any of your other systems. Your first update can't regress any bugfixes.
The longer you've been in business, the more complex your company's systems are going to be. A certain amount can be done to minimize this, but only so much.
Also, the longer you've been in business, the more customers you have, and the more those customers rely on you.
And once you've gotten the system stable enough to sign contracts that include SLAs, you have that to worry about.
In a properly run company, those meetings exist because they are needed to keep the company on track and avoid hemorrhaging money due to bugs and mistakes.