There was a law at our house when I was a child. Gifts were to be acknowledged with thank you notes. The only exception was if you were there to say “thank you” in person, and even that concession was given reluctantly. I always had a particular dislike for this rule, and sad to say in retrospect, I’m not sure I did a very good job passing it on to my children.
Writing thank you notes is no fun. It is a chore, plain and simple. The only way to make it bearable at all in my experience is to write a “form” letter and just copy it over and over inserting a description of the gift in the appropriate place. Sure, it sounds insincere, and it is, but it complied with the law. You’ve got to be careful about this strategy, though, just in case the givers, often related, compare notes.