You raise some legitimate concerns, but there are workarounds for nearly all those issues. Most SAR calls happen on the weekends, when most volunteers are free.

The typical SAR candidate already had some sort of experience in the outdoors, usually in the local area of operations, and had most of the required gear, which was primarily what you might need on a demanding weekend hike. Training, as well as operations, tended to occur on the weekends.

many of our members were college or high school students - flexible schedules. Many of us had jobs with some flexibility and/or understanding supervision that realized the brownie point and public appreciation our efforts garnered in the community.

For all kinds of reasons, not everyone could respond to every call. We had about 80 members on call. A typical operation would result in about 20, plus or minus, responding. Whatever the number, we had enough to get into the field and do some good.