If the user needs to set their own width by resizing the window they can also set the width by right-clicking -> inspect element -> disabling the CSS style on the div that gives it a max width. Which is only a couple more clicks than resizing the window and affects a lot less people.
Often not so easy to do with nowadays bloated designs and tons of patronizing
frontend devs making websites. You might have to remove 10 styles for all the bloat containers they used to contain fancy text. Better to not prescribe any preference and enable the user via standard browser tooling, which definitely would spring up, if users showed significant interest in such.
