What would you prefer? Having an entire paragraph of text on a single line? Your monitor is the wrong shape.
Any web designer who doesn't, in 2021, understand and make allowances for 4k/5k ultra wide monitors as well as phone sizes screens in portrait mode - isn't doing their job right.
The problem here is not the monitor shape or the user's browser window width, it's the css (and maybe html) and the lack of understanding of how to use it properly (or, more sympathetically, perhaps a conscious choice on the part of the people paying for the website to not allocate enough budget to cover all their competent webdev's suggestion?)
1. Have an ultra wide monitor.
2. Regularly use their browser in full width mode on it.
Pretty much everyone I know with an ultra wide snaps their browser to the left or right side - having a single browser window that wide is not very useful, and makes lots of websites look weird.
http://motherfuckingwebsite.com/ looks great on an ultrawide. It's pathetic that so many websites don't.