I use NoScript, so I can give you an idea of what it will be like. A large number of sites will just fail to work (in unexpected ways). Many sites will also look terrible or the layout will be a complete mess. Lots of sites will still display their content and for those that do, you'll probably find they load faster, but they will also probably lack a lot of functionality and often content will be missing because javascript is used to load content from other sites into the page. One particular annoying trend is sites that use javascript for links. More and more sites these days won't even display a single thing - even for displaying text because for example they use client-side templates or make Ajax calls to load the actual content. Javascript has its uses, but so many sites abuse it heavily. Not to mention it's a massive attack vector for malware and tracking of all kinds.
The genie is out of the bottle now. Security and privacy are an ongoing battle. There is no solution, you can only be vigilant and try to keep out blatant attempts - like people hosting javascript files within iframes or ad agencies that use know addresses. Browser extensions like NoScript, uBlock, Privacy Badger do a reasonable job stopping unsophisticated attempts and also help prevent downloading MBs of resources from god knows how many other sites. There is no safety or privacy online. Five Eyes watch literally everything you do and they share their data to circumvent local laws. Advertisers create ever more sophisticated methods of tracking you.
NoScript only makes browsing really inconvenient at first though. You can whitelist individual hosts, or individual hosts but only for certain sites, so once you've gone through the process of whitelisting the minimum set of hosts you need for the sites you use to work you won't notice much difference.