yes. some user data is necessary to collect for compliance reasons, service reasons (e.g. your doctors office stores your phone number so they can give you your lab results), some companies collect it just because they can and they may be able to sell it to brokers/the government later. companies will also use user data to improve their products (e.g. your browser asks to collect anonymous diagnostic data). the world of data is unfathomably enormous as large quantities of data can help make conclusions on anything about anything.

The data can still be collected and sold without advertising being a factor.

Yes but not nearly as valuable. Google’s revenue is almost entirely from ad delivery, for example.