They do the work for you. You could just buy a Pixel 6 and throw GrapheneOS on it, but this is not financially viable if you count the hours needed, especially if you want to recommend a secure phone to non technical friends and not configure it for them.
https://grapheneos.org/install/web is easy to use and GrapheneOS has broad app compatibility these days via sandboxed Play services (https://grapheneos.org/usage#sandboxed-play-services). We're working on making the out-of-the-box experience nicer via a first party app repository and client which can be used to bootstrap installing other app stores too. There are over 6400 users in the GrapheneOS Matrix room with many experienced people always around at any time of day that are willing to spend lots of time helping new users.
I use Grapheneos. The Matrix room #grapheneos:grapheneos.org is everything strcat says it is: yet get used to OpenBSD or Arch levels of "RTFM" as responses to queries. To be fair the docs at grapheneos.org are fair (nothing like OpenBSD's), but without a good grounding in infosec terms of art, they will be between strange and unintelligible. Backscroll search is vital.
Just found their "About the company" page: https://www.nitrokey.com/about
They say that they are totally self-financed and produce their Nitrokeys only in Germany to prevent supply chain attacks.
I wondered if Crypto AG (the swiss company selling backdoor'd hardware) would have said the same thing and looked up their old about page. [0] In light of the CIA's involvement I find it exceedingly cheeky:
> We are present around the globe in all cultural environments. The threats, challenges, and fears you are likely to encounter are known to us; they are the source of our innovative thrust.
Thanks to our world-wide network and regional offices, our presence and services know no borders or limits.
I am using their FIDO 2 USB-Keys for 2FA. First I was sceptical too, but they are on the market for quite a while and I like their fully FOSS approach which Yubikey does not provide. Some of their products seem a bit overpriced, because you can do everything by yourself, but if I count all the hours and days spent with unlocking Bootloaders, searching ROMs and debugging them, this offer seems worth the price.