Foot orthoses or supports are built to correct biomechanical issues of the foot and to improve the biomechanics of the feet. There are many different kinds of foot orthoses and techniques of fabricating them for doctors to use and choose from. Some people require and do benefit from customized foot orthotics while others can be helped by the easier and cheaper mass-produced foot supports. Which one is best for each individual is based on precisely what is causing the problems and what the treating doctor advises is the best for that person. Many different foot orthoses include diverse design features and a good clinician will attempt and match those up to the needs of the individual. If this is not done correctly, then there may not be any improvement in the issue.
Foot orthotics are not without their issues. If they are not the right one for the individual, chances are they won't help. You are also constrained by what shoes you need to use, in that you have to be able to fit them into the shoe and there might not be enough space. There are also varieties of shoes, such as the flip flops which they simply can't be used in. This can cause a challenge in warmer climates that make closed in shoes necessary for foot orthotics uncomfortable. There are alternatives, for instance, the Archies that have a foot support built in. The design of the arch supports in these sandals resemble what you will get in an over-the-counter arch support, but most likely not as good as what you would get from a customized foot support. Using these do give you a practical replacement for foot orthotics, based on where you can wear them and also the nature of the biomechanical problem. If you do need to have foot orthotics there is no harm in trying these types of options or raising it with your treating podiatrist to determine what they believe is best for you.