With my stage 4 cancer (one spinal metastasis, treated with debulking surgery and SBRT), the expectation is that I'll be on ADT + ARSI forever, or at least until there's a major medical breakthrough. As @jeffmarc wrote, once the cancer has left the prostate there's no such thing as a cure, only long-term disease management, unfortunately.

Next month I will have been on ADT + ARSI for four years. The side-effects became easier over time for me, but as I type this, I am sitting in front of a fan in the middle of a major hot flush after overexertion (they've gotten much rarer, but they can still happen). Still, the amazing thing is that I'm not only alive after four years but have no evidence of disease progression, something that would have been less likely 10 years ago with a stage 4 prostate cancer diagnosis.