Theres no accountability above a certain level. In a stable business (am excluding new innovations), proving or disproving the performance of an entire org, let alone company, is extremely difficult. Individual contributors are much easier to judge, and thus live lives of sub-ordinance. Their inputs and outputs can be easily mapped. The trick of working, and thus living a nice life, is to rise to a level of plausible…
The problem of a diverse shareholding base supervising a company has not been solved. If you are an unhappy shareholder, you don't push for change...you just sell and move on to the next one.
Within tech, there is also a cultural issue because so many of these companies end up with VC-led boards or VC-selected managers who are, to be frank, quite terrible (that is the problem with 20 year management teams...the problems of a large company are different to those of a smaller one). Growth at any cost always ends badly. Interestingly, I think some of the companies that went through the late 90s ended up internalizing that...telecoms did, some of older chip companies, unf most companies will always end up learning this lesson too late.