Want to send a message out there to everyone with a bad manager to discuss it with your fellow employees, even better in a space where you aren't being monitored by them. I'll use my example to highlight the importance of it.
I have a bad manager at work and at first it seemed like he picked on me all the time for everything. It was only later on someone came to me saying how they feel like he always picks on them. It was then I knew I should ask others, so I asked around individually and found out everyone had shared the same feeling. That's when I also found out someone made a group chat specifically for us to speak freely with each other as in our job we are left to ourselves most the day. The manager knows this chat exists and makes it well known to the creator his dislike for it and even asks to have it closed down but I don't think he can do anything about it.
The creator of the chat said how managers can divide their employees so that they can get away with stuff, nothing illegal but stuff that can make you feel shit at work and unsure what to do. Said it's a way for people to get the truth out about how they are treated.
So for anyone out there that feels a bit isolated from your colleagues in a bad environment, reach out individually and have a space to talk freely as a group, it's really good to come together as a collective because it does in some cases like mine power down a manager.