Put in minimal effort. The more you do, even if you’re pushing yourself, they will continue to pile on to your workload without giving you anything extra.
This has happened to me several times. People leave, so you pick up the slack, and they see you can do it. Even if it’s at the expense of your mental health. They stop replacing people and just have you do more.
People always say “if I died my employer would have me replaced by tomorrow”
I always say if I died they’d just divide up my workload and eliminate the position