A non-business PhD is not automatically a disadvantage. Firms recruit advanced-degree candidates because they value rigorous problem solving, not because every PhD studies a commercial topic.
The key is translating your background. The PhD-to-consulting without business experience guide explains how to build that bridge.
Show that you can learn unfamiliar industries, communicate with non-experts, work in teams, and make decisions from imperfect data. Business exposure helps, but you do not need to turn your research field into a consulting case.