Requiring a credit card for a free trial is a technique to trick people into paying for a subscription when they normally wouldn't have chosen do do so after the trial period.

Not taking VC funding doesn't make this kind of dark pattern any less scummy. Fundementally you are trading some voluntary customers (people who don't like these tactics) or involuntary customers (distracted, busy or lazy people who forget to cancel.) When I see a company that does this, it tells me that they care about extracting value from the market than providing value to customers.