This reminds me of what my PhD supervisor told me as he was trashing my first draft of my first paper: “up until this point in your life you’ve been trained to convince someone who knows more than you that you know something by writing impressive equations and complex concepts. Now you are the expert and if you do that nobody will read your papers. And if someone stops after a few sentences you’ll lose citations too.”

Similar experience with my bachelor's thesis after I presented it.

Supervisor: "Great job with this."

Me: "The assessor didn't seem too impressed."

Supervisor: "You should have sold it better."

That was the point where I realized that all the technical stuff doesn't really matter if nobody realizes how hard it was or why they should care.

What was your PhD thesis about ?