EDIT: oh, i misunderstood, its just the prompt at the start of your shell... I dont think ive ever been annoyed at how fast that renders either
Of course the fastest thing is to just not stuff your prompt full of detail.
If I still used bash, starship would be a non-starter for me, in part, since it's fork/execed in the prompt command. Further up this thread someone says that the zsh installation is different and it's a native shared library that gets loaded into zsh. That seems neat.
(The other reason it's a non-starter is that maybe I can stomach sending over a dotfile to various systems, but selecting a platform-specific native binary is too much configuration management to be done to prepare for an SSH session/kubectl exec. Eventually I made my peace with doing this for emacsclient so I could have local editing of remote files, but that's a lot less critical of a piece to miss than something that appears in your prompt. Conceptually, if you want to ship over/config-manage a native binary, you might as well install a better shell, which became a compelling argument to me when I switched to Powershell).