The Web Almanac 2019 is just out. It is an insightful survey of websites and the technology behind them. All backed up by robust statistics.
" Our mission is to combine the raw stats and trends of the HTTP Archive with the expertise of the web community. The Web Almanac is a comprehensive report on the state of the web, backed by real data and trusted web experts. It is comprised of 20 chapters spanning aspects of page content, user experience, publishing, and distribution."
It makes for a fascinating read.
I found the report on the use of Javascript in web pages the most interesting but it also covers the use of 20 other subjects; CSS, CMS etc,