I do that. One discovers that some sites include a dozen of third party js. Often enabling the first party one is enough. Sometimes I have to enable some obvious js for displaying videos or comments. Many sites work well enough and display their content without all the related links, advertising, trackers etc. Some sites insist using js to display content that is already inside the main html file. Others break because their main script cannot handle the failure to load some other file. That used to happen when blocking Google analytics. The popularity of adblockers fixed that.

All considered it's an interesting developer experience and the sites I work on keep working even if some scripts don't load.