The mantra of “make yourself irreplaceable” is bull. They don’t care.
1.) All it does is tell them that they can pile more jobs on you and you won’t balk,
2.) You WILL end up absorbing other peoples’ jobs,
3.) “Time off” will be a fever dream, and
4.) They. Don’t. Care.
When you inevitably burn out, you will be tossed aside all the same. Advocate for yourself. No one else will.