What a modern phone system actually includes
Calling that follows the person
One number reaching a desk phone, a laptop and a mobile, with the same extension, voicemail and call history in all three. Much of the cost case rests here, because desk phones stop being mandatory.
Call flows you can edit yourself
Menus, queues, hunt groups and after-hours rules changed in a browser in minutes, rather than logged as a request with a carrier. This is the change administrators notice first.
Meetings and messaging in the same licence
Video, screen sharing and team chat bundled with calling. Whether that is a saving or a duplication depends entirely on what you already pay for elsewhere.
Reporting that shows what is happening
Who is on the phone, how long callers wait, which queues abandon. Basic in every platform, and genuinely useful the moment somebody owns it.
How the platforms genuinely differ
Feature lists converge. These three shapes do not.
What actually breaks, and what we plan for
None of these are exotic. All of them derail projects when they surface late.
Platforms we assess for this
Each has its own page, with the same honest fit guidance.