Which do you prefer, single functionality or all-in-one package?

Sometimes we want few functions focusing on single pin-point, but sometimes all-in-one seems a must-be feature. All-in-one spare more benefit to users while sacrifice the concentration. It depends. So which one do you prefer or you can name some product. For me a solid scenario all-in-one is more powerful because it benefits user the most. Of cource our big notion solves the writing needs all along. Slack meets online communication and brings more with open eco system.