There’s other engine designs (ex:rotary engine) but the 4 stroke has over a century of testing, improvements, and refinements. A new design can adapt some of the refinements, but would have to catch up on decades of innovation and testing just to catch up!
On the Unix side, there’s the evolution of the Posix standard (which was based on Unix).
If the underlying concept is good and was well thought out, it’s better to build upon it instead of reinventing it.
Look at the 4 stroke engine (and engines in general) many of the design concepts date back to the 1880s!
There’s other engine designs (ex:rotary engine) but the 4 stroke has over a century of testing, improvements, and refinements. A new design can adapt some of the refinements, but would have to catch up on decades of innovation and testing just to catch up!
On the Unix side, there’s the evolution of the Posix standard (which was based on Unix).