Xpub sharing is a way less efficient way of sharing a series of addresses than silent payments.
In the video, starting at around 23:30 those differences are analysed.

But the summary is: you should share your xpub only with those you are confident sharing your privacy with, as they would be able to track all your received payments scanning the addresses generated from such xpub.
Silent payments instead break this allowing you the total privacy (with the “scanning costs”).