There’s been a gradual shifting away from really old designs on equally old and/or ‘hardened’ process nodes, simply due to the age, cost, and performance gap. Also older chips didn’t have the redundancy, self-correcting, and failover capabilities of modern processors, so some of the perceived risk from using much more modern nodes and chip designs is being offset by the redundancy modern chips can provide.
There’s been a gradual shifting away from really old designs on equally old and/or ‘hardened’ process nodes, simply due to the age, cost, and performance gap. Also older chips didn’t have the redundancy, self-correcting, and failover capabilities of modern processors, so some of the perceived risk from using much more modern nodes and chip designs is being offset by the redundancy modern chips can provide.