> Once the code for all destinations lived in a single repo, they could be merged into a single service. With every destination living in one service, our developer productivity substantially improved. We no longer had to deploy 140+ services for a change to one of the shared libraries. One engineer can deploy the service in a matter of minutes.

If you must to deploy every service because of a library change, you don't have services, you have a distributed monolith. The entire idea of a "shared library" which must be kept updated across your entire service fleet is antithetical to how you need to treat services.