I don't think anyone can beat Dennis Ritchie on the "designed languages on which trillions of dollars of commerce depend" metric, especially when we consider the many languages which are themselves implemented in C.
That would be joint credit with core innovation going to Martin Richards: the inventor of BCPL that B and C were based on. His team went from big, safe languages to a tiny, efficient one close to the machine with philosophy that programmer was in control. Ken Thompson picked it up from him on MULTICS project.
https://arstechnica.com/tech-policy/2011/07/should-we-thank-...