Midex 3 & mac Sierra

But why, if I buy a hardware, after a few years, can I find drivers anymore?
I did buy the midex 3 to all the students of the music school.
In total nearly 50 midex 3, and today, we have the obligation to have Sierra Os x (to have cubase 9), there are no more drivers for this operating system.
I’m really quiz off.
A product that does his job well, is being discarded …
But, Steinberg also thinks of who works with his products?
Updating a driver is really a tiny job.

I’m sorry for my english

For the joy of Steinberg
With the school we purchased 49 midi interfaces
M-Audio

Thank you