Yeah, it's a business decision, no doubt. The only thing is that when a solo founders make their products, they tend to ask users information just "why not"?

I mean, the thinking process is like:

- Okay, we need a sign up form - Let's make users table - Okay, first name, last name, password, email - Okay, now let's make the form: first name, last name, password, password confrimation, email

While some apps just ask your email even without password :)

Of course if business needs those fields, then yeah. Just when developers work as businessmen, they tend to ask too much.