Typescript is more of "firmly" typed than strongly, in my not so humble opinion.

I guess it's beats C for IoT, but with Typescript it still feels like the S in IoT stands for Security.

The consequences of a type unsoundness in TypeScript are typically much more benign (an exception typically) than in C (a buffer overflow, arbitrary code execution, etc.). Also the application logic is more visible in TypeScript just due to it being higher-level - there isn't so much low-level detail (ever done JSON in C?) so less chance for a mistake.