Contacts on your iPhone are synchronized with iCloud, Google, Outlook, and other accounts. You can delete them on your smartphone, on other devices that are connected to your account, or through the web version of iCloud on your computer or iPad. Let's look at the features of each option and how to use them.
If you only need to delete a couple or three cards, single deletion, which is available from the iPhone itself, in iCloud, and on Mac, will do.
Unfortunately, selecting and deleting multiple contacts at once is not available in the standard phonebook on the iPhone. But you can do so in the web version of iCloud on your computer or iPad, or in the Contacts app on your Mac.
The situation with erasing all the cards is the same as with deleting a few: it can be done through iCloud and in the app on the Mac. In addition, there is a specific option available on the iPhone - disabling account synchronization, after which contacts will disappear from the smartphone but will remain in the account. That is, it is not a complete removal from memory but only from the device.