1. The reason so many BaaS companies partner with existing banks is because the process of getting a bank charter is incredibly time consuming and expensive. There are tons of costs just in legal/compliance before you've even done anything. I'm not 100% clear if Column bought an existing chartered bank or got a new charter, but either route is millions right off the get go.

2. As you point out, they were at 3 years from founding to launch. That's an eternity in the VC-funded startup world. Most startups have an initial MVP in a ~6 month time frame.