The acheivable goal of lockdowns outside of effictively island countries is to keep hospitals open with sufficient capacity. When hospitals don't have enough capacity, any reason to go to the hospital has a worse outcome. Physical beds are one thing, but staffing is a bigger issue.

The problem is it's a tricky system to manage. We can measure hospital utilization, but that lags infections. We can mandate lockdowns, but compliance varies and too many changes risks more non-compliance.

Also, there are existing reasons leading to too many people in hospitals that reduces capacity. And systemic issues that make staffing a challenge.