Just as one example: Chrome + uBOL on Reddit will show you plenty of "Sponsored" stuff. You can use Inspector to find the offending CSS classes and then use `display: none` on them with something like Stylus[0], but not everybody wants to play that whack-a-mole game on the many sites that push uBOL past its blocking capabilities.
[0]: https://github.com/openstyles/stylus