It is open source and on the Mozilla store, did you get the right one? The idea is that you whitelist the websites you trust so only trusted sites can execute js. A lot of websites have js free alternatives like libreX/Y instead of google. There also is GNU librejs which only disables js that doesn’t show its source code. It being a main component of the tor browser tells you a lot about the threat level it’s for. As I understand it the difference to ublock is that it’s lists are on a “allow all but” basis and noscript is on a “block all but” basis.
Emulation is a great for offline gaming. You can also find some great FOSS games on flathub like srb2, srb2k and Mindustry. You can also get old books for free on Project Gutenberg and audiobooks on Librivox. In Germany (and other European countries) there is state financed tv which has free drmfree adfree and (relatively) privacy friendly streaming services. Newgrounds also is a treasure trove, especially for music. Also there is piracy