Perhaps what keeps it so dominate in the space is its plugin ecosystem. You can pretty much do anything with it with off the shelf plugins, and a metric fuckton of duct tape. Headless options are way better, but you need to implement stuff yourself. Which of course is a massive barrier in many cases, but when you have the ability to do so, it ’s almost always better to do so.
Sorry, but... what ? I could literaly start a business called "Wordpress Rescue Team" and make a living with this if I wanted to get my hands this dirty. The number of times I had to clean the mistakes users do when given an admin panel...