I like both projects and they both have their place. My understanding is:
-Calyxos is less secure but more usable day to day, since most apps work.
-GrapheneOS is more secure but less usable day to day since major apps don't work.
Metager.org is my go to google search replacement. I imagine (although my German is non native) that the German search results are quite good. . . it being a German search engine. To be honest it the only search engine to get me off google - DDG is OK, as is searx, but I kept going back to the dirty G until Metager.