Single biggest
technical thing, anyway. IMO, the single biggest thing is focus and clarity in their communication. If people without a working mental model of software development can’t instantly understand the tangible problem it solves in their existing business process, they won’t even scroll past the break, let alone pay for it. Consolidation and modularity are solutions, but people don’t go shopping for solutions without a problem. Have you ever gone out looking for a better commercial version of work-related software you didn’t have any problem with? “App chaos” is way too abstract of a problem for most people to grasp. Do people have trouble sharing google docs over slack? Do companies have trouble with sharepoint and teams not being integrated enough? Does your tool do it better? Does your tool do it approximately as well, but cheaper? More reliably? If so, do people find the existing solutions too pricy or unreliable, or does that not impact them enough to care?
Unless they define, upfront, specific problems people really have, that their unified solution solves, then nobody is going to pay attention.
The second biggest problem is having an interface design team that makes all of those disparate apps consistent enough to be more usable than individual solutions. The fact that nearly no popular user-facing applications are developer-managed FOSS (as opposed to Firefox/blender/signal/et al which are managed by a company that hires professional designers) despite being free, tells you everything you need to know about dev-driven UI/UX. This is coming from someone that worked as a full time developer for years and contributed many thousands of hours of coding to FOSS projects before switching to design.