'They won’t stop guilt tripping me about [...] abandoning them when they’re understaffed': Employee gets new job leaving toxic employer, faces poor treatment from their soon-to-be ex-coworkers

Nothing breaks familiar bonds between once close-knit coworkers, who have bonded through commiserative mutual suffering at the hands of a toxic employer like the eventuality of one of them leaving. 

As the realization dawns that they're going to have to continue on in the world while their coworker is freed, stress sets in, and the toxic atmosphere takes hold. Then they collectively turn on the leaving coworker, partly out of jealousy at their newfound liberation and partly because turning on their departing own is the only way to keep ever-watchful management off their own backs, feigning condemnation of dissenters and ensuring that the neurotically fearful and watchful eye of Barad-dûr (the dark and haunting refuge of c-suite executives) isn't drawn towards them. 

While it's a relief once you finally exit the threshold of that workplace for the last time, it's not without its challenges; you can almost guarantee that any time remaining in your notice period will be painfully drawn out as sharp glances and snide passive-aggressive comments slowly chip away at your resolve. You might consider just staying after all, especially when a generous counteroffer is floated your way despite the fact that you were told there was no money in the budget for raises months prior.