SPARC was the solution. It's open and royalty free and was sold by multiple vendors. Add to that Open Firmware and you're done. It's also not the hacked up turd that x86-64 is or the fragmented mess that ARM is.

Problem is it's dead.

Going out on a limb here, but we can solve this with another layer of abstraction in the long term. We need to develop a fully portable open source virtual machine model (think p-code machine) that is portable and make that the canonical hardware abstraction. That makes all vendors irrelevant if they can't comply with it and opens the market to new hardware vendors with different sales models to provide an optimised hardware implementation of that abstraction. The incumbents (ARM, Intel, AMD) can't sell a security model if the abstraction denies them that ability. Sure they can sell you out, but new competition which is privacy focused should end that.