Additionally, Firefox has the recommended extensions program where they take the most popular/functional subset of extensios in a given category and manually vet the code for security and privacy issues.
I recently found out that on Firefox Android you can install an extension from file by activating developer options. This allows you to install Bypass Paywalls Clean even though Mozilla sadly pulled it from the extension store.
Seems less sketchy to use uBlock Origin with bypass-paywalls-clean-filters... at least then you're not directly adding executable code, though I'm not sure if uBO filter lists can be exploited.