Sort of. It's a slavery that you choose, and that you can end any time. So it's not REALLY slavery. But in your behavior with them, it approximates that. You're doing everything you can to accommodate their needs.
(As the customer I never take advantage of this or look at it that way. And most people don't. But as the provider, you should look at it like that. Maybe not in those exact terms, but it should be your commitment to accommodate them.)
It's interesting that the anarcho-commy/SJW types often feel like a "slave" to their boss or employer.
(I'm not trying to put words in their mouth or sensationalize them. I mean I've heard people actually describe it as that -- and if you search Reddit or whatever, you'd probably find it right away -- and it makes my head hurt. I wish I was putting words in their mouth, but I'm not.)
Obviously, CVS doesn't hold a gun to your head and make you work there. If you accept the rules of that game, because you'd rather work there than not work there, I don't get how people can arrange that in their mind as slavery.
I always figured it was misdirection for what they're feeling about the type of government we have. (Taxation and all forms of coercion against your life's will and what you'd freely choose is akin to a slave/master dynamic.)
Maybe that's part of it.
But more directly, I bet it's like they're slaves to the customer and don't totally get that that's going on. A business that's running rationally or optimally would have all parts of it geared to serve the best interest of its customers. And that includes the staff.
There are various boundaries and rules and adaptations and challenges and effort etc that you have to undertake to make it better for the customer.
With an entitled attitude of like "jobs are just here, sort of randomly, I show up and they pay me", disconnected from the actual point of what you're doing, which is to provide value for someone else, I can see why they'd feel like a slave to their employer or immediate supervisor or whatever.
And some bosses I'm sure suck and do enjoy dictating people around for the sake of doing so. But theoretically and under good conditions, they're just facilitating what the customer needs.
So if you feel like a slave, remember it's to the customer.
And remember that that's a good thing, because if they weren't there and they weren't happy, then you wouldn't be getting money.