Yup
Acquisitions NEVER benefit customers or employees ...
Never say never: sometimes a larger company will buy a smaller company that's on the verge on going out of business, preserving some of the jobs, and continuing the products or services the smaller company produced/provided. For a recent example, the reason you can still buy Twinkies is because Hostess was bought by another company (Smucker's). The customers benefit (if you want to call it that) by still being able to buy Twinkies, and the employees who were retained benefit by not losing their jobs. It's likely in these scenarios that if the company was failing due to poor management, then better management might result in reducing headcount, and obviously those who lose their jobs do not benefit, but it's not as absolute as your statement indicates.
There are plenty of other instances, such as the specialized software I work on now - the company that originally produced it was acquired about 15 years ago by my company, and not only did the software keep being made, and the employees who worked on the software keep their jobs, but the product was able to benefit from integration with other data and software made by the acquiring company, benefiting the customers by creating a more powerful software solution.
There are plenty of instances of companies amicably combining their resources to craft a more capable widget where nobody loses out, but those don't make headlines, so our perception is skewed.