In my experience, it depends on the size of the enterprise and their requirements. Many can get away with just using Active Directory GPOs for Application Distribution, workstation/server configuration etc. and WSUS for patch management. If you are running mainly Microsoft Apps, this works just fine in most instances.
It starts getting complicated when the organization starts getting larger, there are more sites and the types of application that need to be distributed and maintained increase. In many cases (again if Microsoft Apps are the norm), remote WSUS servers can be installed, and remote distribution points can be configured.
Eventually, though, there reaches a point where you need a suite to properly manage and distribute software (especially if you aren't using Microsoft software, which WSUS can't patch). Microsoft's solution for this is System Center Configuration Manager; there are definitely others, though I am not going to recommend any, as I don't use them. SCCM is a beast, and while exceptionally powerful, it isn't something to enter into lightly. If you go down this path, expect a roll-out period of several months, minimum.