The fact isn't that I consider orthotics to necessarily be a detriment and that they don't have their place; rather, I see other alternatives to attempt first, for a client's recovery, before going with the orthopaedic support route.
Orthotics went through a phase of being heavily over-prescribed for a couple decades, with any sign of a flat or stiff arch condoning their recommendation.
It is true that structural changes in the foot, such as a flat arch, might contribute to a higher rate of overuse injury in the lower body. However, it's important to remember that your arch is maintained by both ligaments and muscles, and so it stands to reason that exercise and strengthening can help to improve that arch support on its own. In fact, some studies find that exercise has a greater benefit than artificial insoles.
As well, it's important to point out that, like with any crutch or support, having the support of an insole can actually decrease the strength and stability of your foot muscles due to lack of need.
What's more, if formal exercise doesn't work for you, minimalist shoes are also shown to have identical positive effects on the strength of those small foot muscles.
Again, this isn't to say that orthotics don't have their place. I will always attempt and monitor the effects of exercise on its own first, and so far all of my clients have had no need for anything further. But if an individual's foot structure, whole-body condition, and specific injury require the extra support, then it should absolutely be encouraged.
BUT (this is the last 'but') it's also important to highlight that expensive, custom orthotics are found probably be no more effective than off-the-shelf insoles, so for those looking into the arch support route, consider giving this a try before making the larger expense.