Got the same issue.

I am using an old mac too, if i want to test historic programms which cannot be virtualized on my newer mac. The older mac than supports the older devices over direct connect via usb cable.But as others say, there is a lifetime cycle for both - app development and devices. The lifetime cycle by apple is much longer, than by any other devices or systems. Using a device as long as possible is a strategy, also supported by apple. But sometimes it could be helpful to rethink about the own lifetime cycle support, because with new technology new capabilitys are available. Accessability for example is a topic, which is much better included in the modern development environment, than in the older versions.