I tend toward your side of things. In your first 0-n years of experience, you're growing extremely quickly (hopefully). You're working with a lot of new tech, new people, if n is greater than 4 or 5, hopefully at least two companies if not three. But by the time you have n-teen years of experience, it's much more like you've been repeating the same year of experience over and over again.
Growth, especially if you have a decade of experience (and not one year ten times), is hard. I think especially at the upper end it takes dedicated effort.
I stopped learning programming skills on the job about 7 years ago.
Today, Im still learning new languages, frameworks and libraries.
I'm also still growing in regards to,
Management skills, project skill, leadership skills, self time management, effective habits, not to mention work life balance things as my life now requires it.
Growth, especially if you have a decade of experience (and not one year ten times), is hard. I think especially at the upper end it takes dedicated effort.