The issue at hand is that these web sites lack accessibility information on some of their controls, making them difficult or impossible for a non-sighted user to interact with. This isn't a problem unique to Javascript; back in the day, one common cause of accessibility woes was the use of unlabelled imagemaps for navigation.
Last year, I would try and open the Louisiana department of health website to look at covid statistics, and it would require about 70MB to load a small little box that displayed some numbers. The popular ArcGIS covid dashboard by Johns Hopkins was the same situation - a single page app that took tens of megabytes to load and was very slow - to the point where it would crash on my computer. It's made me think that specifically for issues of public health and public safety, a priority should be placed on making sure those websites load quickly and run smoothly.
Edit - I misspoke when I said it needed 70MB to load - it was 9+ MB of data transferred, 70+ MB resources. Here's a video I saved of the page loading from last year [0]
For example, if the county dropdown box in the article had been a <select>, it would have automatically worked in the screen-reader without needing to write any additional code.
Instead, today we get sites that need to load dozens of MB of JS that's reinventing the wheel (and forgetting to reinvent accessibility), are hard to use even for sighted people thanks to stupid UI trends like hidden scrollbars and whitespace everywhere, and fail completely if your browser is even slightly older or otherwise unusual.
There's really no reason for overcomplicating things other than web developers trying to justify their salary --- or Google attempting to make its effective browser monopoly even stronger. The continual churn of the web and the "doing less with more" direction that things are going is a horrible disease. This isn't progress; it's a regression.
A very related discussion from not long ago: https://news.ycombinator.com/item?id=25915313