You're touching on an interesting point, so sharing a little data over time is less of an issue then sharing your entire life story all at once. Thinking of Facebook which slowly learned more and more details about all it's users and people where willing to share pieces of data that maybe otherwise would have shied away they would have been asked about all their data upfront.
To your second and last point: I think one can share all the data one want's the more difficult part is using said data. Under GDPR there are very tight limits on what one can use and what not, even inferred data are personal data [0] so I'd say it's a good start for framework protecting personal rights.
https://techcrunch.com/2022/08/02/cjeu-sensitive-data-case/