I don't disagree with you, but a lot of people don't understand any of those steps. 3 is the step most people will understand, I think you can understand that LetsEncrypt can be confusing the first time, and well... DNS... that's notorious for people being confused on.
What people consider "advanced user" varies quite a bit and there's a lot of subdomains in computing. (Though maybe the term is also degrading...)
It strikes me that if you aren’t advanced enough for this then you probably aren’t advanced enough to safely manage your password manager locally. If you don’t have a good understanding of things like DNS, do you understand the vulnerabilities you need to mitigate for in a self-hosted situation? I don’t self-host, even though I could get it working and I self-host plenty of other things, because I’m not a security expert and I think it is more likely I would put my password manager at greater risk than Bitwarden.
What people consider "advanced user" varies quite a bit and there's a lot of subdomains in computing. (Though maybe the term is also degrading...)