Where I come from, the notice period is here to protect the employee: if you get fired, then you know you have a salary for those months. But from the employer's perspective, as soon as you resign they want to see you go; what's the point of keeping an unmotivated employee for 6 months? Are you sure that you would be "forced" to wait 6 months?
> My fear is that, coming from a similarly dysfunctional place, I'll just put in hopes and efforts for a better workplace and end up somewhere even worse
I understand that feeling, I started with a messy startup and followed into a toxic one. Now I am in a healthy environment that I didn't know could exist! I just want to tell you that there is hope, it exists! Keep looking.