This is the limit to what people do. In my field, even source code sometimes isn't free software. However, if you ask a researcher, they will give you a copy yo

This is the limit to what people do. In my field, even source code sometimes isn't free software. However, if you ask a researcher, they will give you a copy you can freely modify, because the act of asking means they know who you are as a person, and can later ask for citations when you publish. Data is similarly treated. Just putting it out there without any barriers guarantees that other parties will use it without citing you.