When an industry is so reliant on one service, it's very difficult to shift an entire industry to a new platform. Segmentation is a real thing.

A good example I'm familiar with is within electronic sports (competitive video-games): almost every executive, player, personality, etc has been using Skype since ~2010. Unfortunately, Skype has a large number of security vulnerabilities and users can be subjected by DDOS attacks- which is especially important if such an attack impacts their performance in a game, or interrupts a livestream. Even though there are, arguably, better products being created that serve the same purpose as Skype and that don't fall victim to this problem (Discord, Slack), those within the industry don't want to segment themselves from everyone else.