You said Arch can do “literally anything” that any other distro could do, and I’m trying to point out that by having to issue imperative command(s) to set Nix up on Arch, you’ve already conceded that the entire state of the system is not able to be declared in a config file, which is one of the features of NixOS. So there is at least one thing that NixOS can do that Arch can’t. I imagine there are other examples (and not only when comparing with NixOS). So again I ask, can you please refrain from hyperbole?

No, because while that lets you use nix to manage some of your packages, it’s still fundamentally limited by being hosted within the imperative Arch install. See for example section 2 in the very link you shared, which talks about starting the nix daemon at boot by messing with your systemd config.

I love Arch but I’d caution you against hyperbole like this. For example, NixOS has a declarative config for the whole system along with atomic builds that can be rolled back or switched dynamically. Not aware of any way to do any of that in Arch.

Start with one site at a time, and if a site/service doesn’t allow you to change your email without contacting them, make a note of it, and don’t worry about it for now. To begin with, focus on the sites that you can change yourself. This will give you a sense of making progress, perhaps faster than you might think.

I started switching off of gmail about 4 years ago and I’m still checking it periodically. Most of the messages I get to my gmail account these days are spam or mistaken emails due to people signing up for services and thinking that my email address is theirs (I have an early “first initial/last name” gmail address that I got in 2005). But every once in a while something legit will pop up and I make it a point to change the address.

I don’t know if I’ll ever actually close my gmail account or stop checking it, but at this point I’ve got 99%+ of the services I care about switched over to my new address, so if Google boots me, I won’t care.