Who can see my phone number
Nobody sees your phone number or email by default - not vendors, not other customers. Vendors reach you through the in-app chat, the WhatsApp bridge and masked calls.
If you want a vendor to call you directly, choose Share my number with this vendor in that conversation. It applies to that vendor only, and you can take it back at any time from the same place.
We store every choice with its date and the privacy notice you saw. See and change them under Account → Consent.