It depends on what you are trying to protect and what options you have if one component fails (replacement). For highly critical systems that is an issue but i

It depends on what you are trying to protect and what options you have if one component fails (replacement). For highly critical systems that is an issue but it is being adressed. Take as example the space shuttle or the Airbus (3/2) primary/secondary flight computer [1] where the backup is being build by different companies with different processors ... [1] https://ifs.host.cs.st-andrews.ac.uk/Resources/CaseStudies/Airbus/Airbus-fcs.pdf https://ifs.host.cs.st-andrews.ac.uk/Resources/CaseStudies/A...