What deflation does is reduce the cost of everything. People who are ambitious and want to better their situation will still work, earning an income. People still require goods and services to survive (and thrive). In a deflationary world you reward savers, who delay their gratification, rather than an inflationary world that rewards debtors, who desire instant gratification.

Again, there is nothing inherently useful nor required about inflation. We can live in a world where prices are stable, decreasing, or increasing. I like the one where prices are decreasing.