That depends. I’ve seen a lot of adaptation to processes that are legitimately & measurably better in time & accuracy ignored in favor of costly customizations out of nothing more than “not created here” syndrome. If a customer doesn’t like that then an off the shelf product is the worst choice they can make unless they are prepared to hire a significant in house dev team.
Otherwise, if you have been adapting your current business processes to deal with the limitations of a legacy system first deployed in the early 80's then there's an excellent chance that at least some of those things can be done more easily in a more modern system. (Though SAP may not always be the best place for that to actually be the case).