DIY applies nicely to outdoor gear. No matter how critical the application, there are many items that you can actually do yourself and use successfully.
Going out there with gear that you have made is incredibly empowering. There’s an added sense of responsibility and success is particularly meaningful.
It also means the chance to design for yourself. Professional designers may be great but they work for the majority or for the brand. No one knows your needs as much as you do.
Outdoor DIY may be work intensive and time consuming. It may even not make sense from a strictly economic point of view but do have this one clear: you can do it.