What would our lives and society be like without antibiotics?

Life without: antibiotics. Morbidity and mortality from bacterial infections would be a lot higher.

Not living as long: Antibiotics have significantly reduced the rate of death from common infections like pneumonia from 30-40% to about 5% with antibiotics. The CDC has an article that shows the most common causes of death in the US from 1900 to 1998, with antibiotics becoming widespread in the 1950s. Infection drops from #1,2,and 3 in 1900 to #6 + 7 https://www.cdc.gov/nchs/data/dvs/lead1900_98.pdf

Check: out statistics for the early 20th century and before, when the leading cause of death was infectious disease, and the average life expectancy worldwide was 30(about 45 in the US in 1900). Antibiotics, immunizations, and improved sanitation have transformed some of the most feared scourges of earlier times into reportable events today.

Shorter: Go to an old graveyard and see how long people used to live. Notice how the number of early deaths get much fewer after 1940, when antibiotics and immunizations started to come into use.