You definitely get promoted for simplicity, if it translates to the real world in a tangible way: When other people are hard to work with because their solutions bear all the hallmarks of being overly complicated or complex and cause problems more often, higher ups or peers might not always be close enough to the technicalities to understand why – but they are not daft and can notice patterns. Attribution will not be fair in every single instance, but it averages out.

People who are easy to work with get promoted, and that is downstream from building simple solutions.