I think the continued success of 5e really boils down to the change in philosophy on supplements (as mentioned in the article). Instead of creating supplements to appeal to people who already bought a PHB, WotC focused on creating supplements that help sell PHBs to new players.
This helps the brand in two ways, both by bringing new players in to buy more supplements and replace those who leave, while also leveraging the value of an IP asset that is already created. This is seen by how PHB sales shoot up with every new release.
In this way, it works much like the MCU. Don't like Iron Man? Maybe we'll get you on board with Dr. Strange, and then you'll go and get a D+ subscription to catch up on the story (and was the reason Disney was ultimately fine with Sony distributing Spider-Man, that character is a massive entry point for Marvel). For 5e, it's, don't like Dragons? How about a Giants or Pirates or Devils or Mythology or Horror or Magic School or ...
WotC focuses on 3-4 entry points for new players every year (just like the MCU) and markets the heck out of them, turning them into events that people who've never played still hear about.
Of course, they also embraced the rise of live streams and celebrity players (hello Crit Role and Sports Illustrated article), and that helped too, but without the switch in publishing strategy, that wave would have already crested.