Would you get fired for an unintentional serious bug in an operating system?
- no stupid sprints
- no agile
So, if a new "feature" needs to be implemented at the hardware level, then all the time needed will be spent thinking about the problem, the design to be applied, the architecture of the design... and only when everything is crystal clear and all the relevant aspects have been assessed (performance, cost, efficiency, etc.) then the implementation can start. Compare that to the "sprint circus" software developers are part of: almost no time for long-term thinking, everything has to be done within the sprint (usually 2 weeks), "move fast and break things".
One bug in hardware for non-safety critical applications are just left there and a revision is done to replace its production. In the most serious cases, a bug in hardware inside a home appliance or safety critical component in a vehicle will trigger a re-call.
Nothing fun about that in HW engineering. Unlike the wild west of software engineering with all that Javascript.