I had every desire and intention of upgrading my desktop (late 2015 iMac) to the newer hardware, right up until they decided this hardware is somehow incompatible with the newest MacOS.
They've basically just ended 20 years of Mac for me.
I hit the same issue back in the 10.4 > 10.5 upgrade days, my computer's OX911 Firewire controller chip just became unstable. No official acknowledgment from Apple, thousands of angry Apple Discussions posts.
