That is absolutely horrible UX: User interaction should not be required for your site to be legible. If you are one of the 0.000001% of people who wants all line breaks to vanish configure reader view yourself and hit that button, but don’t force 99.999999% of users to make that extra click.
…also, nothing whatsoever is stopping you from making line width adjustable within the page itself.
That is absolutely horrible UX: User interaction should not be required for your site to be legible. If you are one of the 0.000001% of people who wants all line breaks to vanish configure reader view yourself and hit that button, but don’t force 99.999999% of users to make that extra click.
…also, nothing whatsoever is stopping you from making line width adjustable within the page itself.