There were ‘people’ around, so what did they do?................
They survived, altering their behavior as necessary, and continued to do the things that make them all our ancestors. People not close enough to be killed adapted just fine.
Despite the best boosterism by volcanologists, the impact of eruptions is at most, regional. The discrepancy in numbers between Greenland and Antarctica is due to the southern hemisphere's being mostly ocean.
Contrary to claims, there was not a genetic bottleneck -- that notion arose from too little data stretched over too much model.
Sidebar: I was curious about this study and Thera, but apparently the period they studied ended thousands of years before the purported "super-eruption" (phone booth explosion graphic). A signal found in a Greenland core was immediately saddled on as Theran in origin, but the chemistry didn't match Thera, and afaik still doesn't match any known volcano.
Lack of a match in that case and in the unidentified cases shown in their graph *may* indicate a marine volcano that long since eroded away, but regardless, unknown indicates no samples have been collected from a known (or unknown) volcano.