If they haven't been fired, it means they're performing the tasks of their job. If they weren't, why would they still be employed when the vast majority of states have at will employment?
Because, at least if times are good, there's a pretty big gulf at most companies between "You're our best employee on our most important project" and "You're an irredeemable screwup who needs to go now." Most companies are slow to get rid of people even if they're just getting by.
Why would they get rid of someone who is getting by? If "just getting by" is inadequate, then they're not really "getting by". The goal in discussing this topic is clear thinking, and these weird, euphemistic/hyperbolic phrases are the enemy.
It is sort of a euphemism like acceptable, "OK", and any manner of other descriptors that we probably shouldn't use as much as we collectively do. But in this context, they mean it's probably too much trouble to push you out the door right now given the hiring market but we're really not feeling the love.