It's both. Some people do genuinely fear the delta variant, even though it is statistically weak and pathetic. Some people like you say are scared of going against the narrative and losing social acceptance. And some people are genuinely afraid of both.

But not everyone's reason is social acceptance. The friends and family I know who have had the clot shot basically know that I think they're idiots. I haven't told them straight, "You're an idiot," but I've gone through the statistics relevant to my age and stated that for someone in my age group it would be statistically idiotic to get it. And most of the people I've said this to are slightly younger than me, so I'm kind of indirectly telling them they made a mistake.

So not everyone is doing it for approval. Some are genuinely afraid of a virus which now kills less than 1 person per day in the UK, and genuinely not afraid of an untested experimental messenger RNA delivery system which has killed over 11,000 people in America (and that figure is only the reported deaths).