People use what they know. Many office employees used PowerPoint before the online solutions were even an option, and many of these same people will continue to

People use what they know. Many office employees used PowerPoint before the online solutions were even an option, and many of these same people will continue to do so until something happens that forces them to relearn something else (and relearning is non-trivial). Inertia is a powerful thing, and PowerPoint has enough mindshare that its common to hear people say "make a powerpoint" instead of "make a slideshow".