I worked for many years in the Columbus pharmacy site in a variety of roles, first for Merck-Medco, then Medco, then ESI until I was laid off by Express Scripts in 2016. Medco was a wonderful company to work for, ESI not so much. If roughly 15 years working for Medco, I saw one round of layoffs. I lost count of the the rounds of layoffs we saw with ESI.
ESI is a company that does most of its "growth" through purchases and mergers and then squeezes the acquired companies in order maximize profits. A primary reason they bought Medco was that Medco had superior computer systems and software capabilities they wanted. Once system integration was completed, much of the rest of what was Medco became expendable--including, alas, the careers of many of my former co-workers.
Someone asked earlier here so I'll say it--yes, Columbus is a work site with a unionized work force. I can't pretend to speak for every instance, but from what I have observed most of the unionized legacy-Medco sites are now gone, with work shifted to (non-union) legacy -ESI sites. The unfortunate truth is that this makes business sense for the company--that is, it does unless the union, employee, and retirement groups that ESI serves as a PBM get tired of seeing this happen and decide to take their business elsewhere. In the current political climate, I would not be surprised to see the company suffer from a bit of backlash on that front that makes it difficult for them to renew some of their contracts...although I doubt that this will be an insurmountable difficulty, nor do I think it will impact a significant piece of their business anytime soon.