OP and others struggling to get in, I have some thoughts for you.
I myself struggled to get through the hiring process. I did finally get through via an uncommon path and after several years of effort, waiting, and anguish. In my mind I built up this career to more than it actually is. After an initial false start, I became even more obsessed with it and saw it as my only path to a good future.
I'm currently at a high-level facility and I can say that things haven't quite lived up to the dream. This is a good job but it has its downsides, too. There are many jobs with way better schedules and more flexibility with using leave, or where you don't face 20 layers of bureaucracy to change anything. And there are many jobs where you can work in more modern, better-kept facilities. And there are many jobs where you have more diversity of tasks, autonomy, creativity, and satisfaction.
Also keep in mind that if you win the hiring lottery, you still face the equally ominous placement lottery. It's easy to overlook this or brush it aside before you even get in, but the reality slaps many new hires in the face. It's not difficult to end up at an undesirable facility or in an undesirable location and be stuck there for years upon years.
Lastly, this career is RIPE for far-reaching automation. 99% of it is memorizing a ton of rules and facts and applying them logically with constant, unerring vigilance. It is literally the perfect application for computer intelligence. The government moves painfully slowly, but it's hard to imagine that there won't be significant impacts in the coming years.
All of this is to say, don't necessarily rest all your hopes on this one career option.