Comment by hn_submit

Another reason is that a lot of tech from 20 years ago uses the QNX microkernel operating system, which is highly secure even when the software is never patched.

The problem is that most of these older devices are about to be replaced and many manufacturers have switched to Linux for their operating system. It's cheaper and requires no licensing, but far more insecure. It needs almost constant patching to stay secure because the attack surface is so large.