What makes it hard, these days?

I did plenty of WP back in the day and I agree, historically, but each of the strong answers I had in my mind (db integration, editor, plugins, themes) are weakened substantially by the AI agents' ability to port a working site to a new framework. I totally agree for normal users still but for devs taking jobs on this do you think the barriers to switching have come down in size?

It certainly is. But I won't be recommending it for new projects. Imagine how bad that would make you look.