Privacy Redirect is a pretty solid addon for automatically using those lightweight open source front ends like nitter (twitter) and invidious(youtube) as well as many others.
As far as search engines go, I really like Searx. Its great at what it does, has lots of customization, and is open source. Being able to host your own instance is important to tech schitzos with tinfoil hats at least 5 layers deep.YACY is a true decentralized p2p search engine and I like it conceptually but as far as disseminating information its not anywhere nearly on par with the centralized ones.
https://encyclopedia.marginalia.nu Is a high-readability wikipedia mirror I prefer using and https://search.marginalia.nu/ is a cute alternative search engine designed to help discover older and more obscure websites you wouldn't otherwise find in a typical google search.