@resist1984 The vendors I buy from could only transfer the special mail address I created for them, which states the vendor in the user part (while the domain part is all mine). So if they do and I receive spam, I can set my mail provider to delete every mail to that address. Profiling is harder that way. But if offered, I use Giropay which I'm afraid again is a European specialty: Vendor directs me to my bank, I login, order the transfer, and my bank confirms to the bank that the order has been submitted successfully and will be executed. No login data, no password, no check code or any personal or secret data is transferred between vendor and bank.
@mupan I do something similar. I use a forwarding acct. Some forwarding accounts us on-the-fly address generation, and some use manually generated ones. On-the-fly addresses are the most convenient, but they always show a username either to the left or right of the "@". Spam control is decent, but the username exposure means anyone with access to my credit file can reach me by email.