Some observations that they to avoid many of the sweeping assumptions some have made.
The personal stories give good insights I believe, if I were in your position OP.
All children I have heard talk of the popular, cool, kids; who tend to be absolute cows to some others, just so long as they have enough 'supporters' around. I have worked in schools with groups on specialist projects and see the dynamic, especially those that 'try' to be with the so-called popular kids .
I remain impressed with those kids that either don't bother trying to be 'in' with the idiots and bullies, or move on their periphery without conflict,seeing through the shallow, and those that try it and move out.
Some schools have a higher percentage if these and it dominates some of the socialisation within those schools, some to a degree that it's cool to not work at school or to try hard earns name-calling. This has been the protocol for years.
Some schools have a great ethos for all students to aspire to achieve and its actually cool to do well, it sounds like your dds would flourish under this ethos.
Like PPs have said, spec. moving to a job where she suddenly was easily accepted.
I have experienced the cool gang, and being berated for doing well, also. I have also been with cool gang kids who who are really quite pleasant kids on their own but ruled by the group dynamic when together,the 'gang mentality'.
My DC have also experienced the popular kids, and one was 'adopted' by them and was continually the centre of jealousies between two particular girls that everyone else seemed to rotate around. She hated having to listen to the bad-mouthing of the one by the other, and vice-versa.
Your dds are well out of it, and I think it's extremely difficult to know anything from what you say about their dynamic around potential friends.
Certainly not enough to make such wild assumptions.
It comes across that you are able to maintain good friendships.
I would be inclined to ask what they are looking for in their friendships, to discover if they have realistic expectations, and how they manage disappointments.
They can also be experiencing the 'trying on' that ppl do, and reacting badly to not being found by others to be a good fit for the other. Therefore forming a belief that 'nonone' likes them and so on.
There could be so many reasons; I also see many kids that do hate their parents and have extremely poor relationships, but am absence of this is not a red flag at all!
Not all teens are the same and some mature very quickly and don't blindly follow others. It's just that some 'gang up' together for strength for their insecurities.
Schools, colleges and unis can be extremely hard to navigate and for some impossible, but that's not always a reflection of any individuals fault to struggle with it.