Any self-respected company should. Yes there is overhead in maintaining an instance, but it is not more expensive then cloud-hosted versions even if such a mention opens a floodgate of those who would want to convince you otherwise with "economies of scale" and whatever arguments.

Cloud instances have issues with noisy neighbours. If there is a performance degradation, a large number of users can amplify it until the whole service is down, such aplification rarely happens in local instances with lower user counts. Jira is a famous example where it got its slowness reputation purely from the cloud version. A local variant can be much cleaner and without extra plugins.

Every time i hear these stories of "github down, guess no work today" i feel like i would fire quire a few people if i was in charge of such a company. I have experienced external network outage while working and it only required changing push target to local git mirror, work continued as if nothing changed. Builds and tests were run on a local jenkins instance.