Corporate takeovers can ruin a job. New workplace policies, new culture, and mass firings. Look at what Elon Musk did with Twitter. When people are being let go, it's insulting when the higher-ups hire your placement and ask you to train them.
To keep it short, 15 years ago, I worked for a local computer programming company that made automation software. Our company got bought out by a bigger national company, and after the dust settled, corporate decided they would send a 'liaison' down to our local office. To 'learn how you do things to be a better bridge between offices.'
AKA: 'Hey, teach our guy how to do your job so we can let 3/4's of you go before next quarter.' None of us were happy, but our new corporate overlords had spoken. A month or so later, our 'liaison' fellow is ready to go.