The article addresses this point.
This change is justified by the fact that a user can simply log out and view another user’s posts anyway. Except that’s not entirely true. Since Elon Musk took over the site, being logged out of X makes it very hard to view a user’s profile, individual posts are viewable but viewing an account triggers a log in pop up.
So technically it is possible for a logged out user to view your tweets but it’s a lot more inconvenient. Anything you can do to make it not worth their while helps.
With this change they won’t even have to put any effort anymore to stalk your content on X.
Just use Google Docs then. Yes, it’s Google. Yes, it will somewhat tie you into their ecosystem but Google Docs are free, get regular updates and are pretty good overall. I’ve been using Google Docs for many years now. I occasionally use Office365 for work and Google Docs is just as good, if not better.