Is there a word for the feeling that something is “off” about an overly pleasant group activity?

Is there a single word for the eeriness that you might feel when you're in a group activity that seems so pleasant, cheery, and safe that you can't help but feel like something's wrong?

The word should fit in this phrase: "Everyone is way too happy, and these streamers only add to the ____."

For example, you attend a child's birthday party. Every single guest has a smile on their face, everyone's chatting with each other, everyone's lively and happy. But it quickly begins to feel so false, artificial or superficial, like an illusion of pleasure. You abstain from interacting with anyone because they all seem like robots programmed for the facade that this party is, unreal or inauthentic. You feel disconnected. Perhaps this is "depersonalization", but the word I'm looking for would imply that this feeling was prompted by the merriment of the event combined with the fact that it was a group activity.

As another example, you observe a concert from the outskirts of its audience. Everyone's jumping around, laughing, and having fun. They might feel like genuine, real people, but you can't shake the feeling that everyone ought to be doing something else, something important, even if you can't pinpoint what that something may be. It's like everyone there is experiencing Peter Pan Syndrome. The idea that they're tiring themselves out by moving around so vigorously invokes a sense of pointless self-harm.

A third example: a VTuber excitedly sings a major-key, upbeat song, giggling off their mistakes every now and then. You notice a count of tens of thousands of viewers under their stream, one of which, for some reason, is you. You begin feeling uncomfortable, like this is all weird to be doing. You feel like an adult/teenager in a playpen, and you close the stream.

Basically, I'm looking for a word that means "eeriness" or "uncanniness", which describes the mood of each situation above, but implies that the source of this uneasy mood is the elation that the group activity would generally be expected to be received with.

Note: The reason the activities I refer to are group activities and necessarily not single-person is that the perception of many others indulging in the activity contributes significantly to the triggering of the feeling I'm looking to describe. Say the above examples occurred without crowds, and it was just you enjoying a song or video by yourself. You might be able to just stop, turn around, and engage in another activity as soon as your subconsciousness asks to move on, and you wouldn't feel any noticeable unease. In group activities, not only are you forced to continue witnessing people indulging in the activity, you're forced to witness them indulging together, and there's always a sense of enthusiasm and immersion in group pursuit that one may cringe at if they feel the mood I'm talking about.

Edit: I'm asking for a feeling, a notion, a descriptor of what one's perspective imposes onto a given situation, not an assertion of the intrinsic qualities of the situation, if that makes sense. For example, "dumb" allows that the quality it refers to may be imposed by the speaker's perspective, because the concept of dumbness must be defined in relation to its opposite -- things outside of what is being described. "Insincere" is not like this, because it's centered on intent, which is an intrinsic quality.

"Everyone is way too happy, and these streamers only add to the absurdity/surrealism/alienation."

To be absurd is to be ridiculously incongruous—in this case, the contrast between a banal group cheerfulness and the viewer's isolation/disconnection/distance/estrangement. Frivolous behavior may seem to have no rational or orderly relationship to true human life and society's greater problems or challenges ("you can't shake the feeling that everyone ought to be doing something else, something important").

Surrealism can involve a juxtaposition of common images (active people enjoying themselves, a person sitting quietly) that may invoke uneasiness or dread ("a group activity that seems so pleasant, cheery, and safe that you can't help but feel like something's wrong").

Perhaps the viewer has a sense of solipsism (i.e., that only she or he autonomously exists; "You abstain from interacting with anyone because they all seem like robots").

There are also aspects of social anxiety disorder and depression ("In group activities, not only are you forced to continue witnessing people indulging in the activity, you're forced to witness them indulging together, and there's always a sense of enthusiasm and immersion in group pursuit that one may cringe at"). Perhaps the viewer feels distaste or aversion to perceived or actual trite or corny enthusiasm—they feel aloof or vicariously embarrassed ("You begin feeling uncomfortable, like this is all weird to be doing. You feel like an adult/teenager in a playpen").