I think what you are referring to is sometimes called “love-bombing.” My Wife belonged to a Brethren Youth Group and they were known for this. Yes, they were trying to bring their peers to Christ and I do believe there were some genuine friendships there, but there was also the goal of bringing people to Jesus.
Your posts reminds me of a book I read in High School called, “The Catcher in the Rye” by J. D. Salinger. The main character feels the way that you do and is constantly questioning the authenticness of others. Holden Caulfield even uses the term “phonies” to describe them.
I actually had A.i. imagine if Holden had a conversion and I think you might enjoy reading it.
At some point, we need to move beyond judging how others live their lives and focus more on our own authenticness. If you texted me on Christmas, “Hi,” I might see you as disingenuous. I do have friends who wish me a “Happy”-whatever and I know that they are my friend, but these well-wishes feel forced (even though they mean well). It is for the same reason I turned off showing my Birthday on Facebook. I did not want all the “Happy Birthday” posts and then having to post the “Thank You for the Happy Birthday posts” post.
I’m glad you differentiated between friends and acquaintances. I have a hand full of individuals whom I would refer to as friends, but many acquaintances. Not because I don’t have a lot of people wanting to be my friend, but because there are very few that I would actually call my friend.
Have you ever met someone who refers to every acquaintance as a friend? My brother-in-law had a million “friends” (but really they are acquaintances).
On the flip-side, I think it would be hard to be friends with someone who is constantly questioning my authenticity. Let’s say that I thought of you as a friend, but you constantly are thinking I am “phony,” then what is the likelihood that we could be friends (I’m not asking you to be my friend ; )
My point is, maybe focus on being friendly rather than focusing on whether or not someone else is being authentic. What is, is out of our control.