Not sure about the corporate sector, but it certainly seems to at least have an impact on American politics. Some 2014 statistics [0] have the average age of representatives and senators at 57 and 62, and several current senators have served for well over 25 years (3 senators right now have been in their offices for over 35 years) [1]. I'm sure it's hard for even the brightest young politician to oust someone who's been in office since before they were born, especially if they're in the same party.
Tenure is a pretty artificial condition intended to prevent controversial research from being eliminated out of fear of losing your job. It seems in the corporate world execs do something controversial, get fired and get paid off. I believe average length of tenure in c-suite positions is actually decreasing, so moving in the other direction without any law limiting it.
[0] https://www.senate.gov/CRSpubs/0b699eff-adc5-43c4-927e-f6304...
[1] https://www.senate.gov/senators/longest_serving_senators.htm