I'll never forget working one of my old serving jobs. I wouldn't say I was the top server, but I was pretty damn good, if I say so myself. Our daytime manager was a total hardass; no sense of humor, no sympathy or empathy, the whole shebang. Like a restaurant drill sergeant. I was still relatively new to the larger world- I'd only been living on my own for a couple years and building that foundation. Long story short, I was going through chemo at the time, and he'd make me come in to do my shift. I was young and stupid and paranoid about money- sure as shit didn't have any sort of insurance- so I always would. On the few occasions I'd try to call out, he'd scream at me over the phone, threaten my job, tell me how I was letting my coworkers down, you name it. So I went in, every time. Don't know how, but I never got sick during my shift, despite having just come from treatment. Must've been pure adrenaline. When I did finally leave the job for greener pastures, on my very last day, he pulled the whole "you're such a great worker, it won't be the same without you here" bullshit.
Don't get me wrong- sounds like the job situation is much better in this case, but still. I've known too many friends and loved ones who were told they were "invaluable" and "irreplaceable", yet when it came time to downsize, they were the first to go or be replaced with someone younger and cheaper.