It also depends on the kind of PE firm. The vulture firms will buy a stable firm and load it up with debt doing stock buybacks and then cash out and let the company crater.
Other firms, like Texas Pacific Group, are turn around specialists that take struggling firms and fix their business processes to make them run better and raise the stock price by actually building a better company.
There are a lot more of the former than the latter, mainly because it takes some uncommonly smart people to run the latter kind of fund and just a bunch of bean counting jerks to the run the former kind.
Other firms, like Texas Pacific Group, are turn around specialists that take struggling firms and fix their business processes to make them run better and raise the stock price by actually building a better company.
There are a lot more of the former than the latter, mainly because it takes some uncommonly smart people to run the latter kind of fund and just a bunch of bean counting jerks to the run the former kind.