It depends very specifically on what sort of problems you develop. It is theorized that when you do suffer a lower limb injury using orthotics changes your muscle activation pattern (moreso than changing your form), which helps alleviate the issue. The rate of orthotics fixing problems after a specific injury is pretty high so it is more than just mumbo jumbo.

"70% of runners with lower limb injuries improve when they use orthotic devices (James et al. 1978; Bates et al. 1979, McKenzie et al. 1985; Gross et al. 1991)..." Noakes, lore of running. So clearly orthotics and what you put under your feet can have an impact and make things better (or worse, but probably better if someone knowledgeable about biomechanics can see your pronation and gait).

Ironically I used some orthotics as a teen. My feet are half flat, some "podologist" gave me curved soles. Didn't work on me. I don't refute the idea; I probably just needed a more comprehensive solution for a prolongated time to make a difference.