Bypass Paywalls Clean - https://gitflic.ru/project/magnolia1234/bypass-paywalls-chrome-clean
To access articles.

Dark Reader - https://addons.mozilla.org/en-US/firefox/addon/darkreader/
Dark mode on all websites.

SingleFile - https://addons.mozilla.org/en-US/firefox/addon/single-file/
Instant snapshot of a page.

SponsorBlock - https://addons.mozilla.org/en-US/firefox/addon/sponsorblock/
Skip paid promotions.

Stylus - https://addons.mozilla.org/en-US/firefox/addon/styl-us/
To modify CSS (font size etc.)

uBlock Origin - https://addons.mozilla.org/en-US/firefox/addon/ublock-origin/
No ads.

Untrap for YouTube - https://addons.mozilla.org/en-US/firefox/addon/untrap-for-youtube/
No Shorts.

Yesterday for Old Reddit - https://addons.mozilla.org/en-US/firefox/addon/yesterday-for-old-reddit/
Old Reddit, desktop and phone.