In summary understand your works impact and considerations and challenges.
If that fails suggest shadowing each other for some time. Or maybe show the impact of your code on the areas he values, eg efficiency improvements.
If it’s company culture then it might not be possible to change by yourself.
Frontend used to be just HTML, CSS, and a sprinkling of JS. Then the engineers took over and JS is no longer a sprinkling. It means build steps, web components, React, integrating best practices, learning new frameworks every month, performance, and a panoply of other things.
Should he says no, there's your answer.
If he says yes he'll do the changes, take a long trip for a month without any intervention from your part.
Then count how many times he begs you to come back.