Many times when people are let go they think it's their fault and that there's something wrong with them. In reality, there are too many gatekeepers/bosses who are complete jerks and their decisions to "fire" people is all about self-preservation. As you stated, the best thing to do is to just move on.
Alejandro Diaz writes about culture, politics, and the workplace. His new business, D & E Management Solutions, Embraces Humanity at work https://dandems.com