It looks pretty, but IMO one of the selling points of zsh is that it allows async updating of the prompt, allowing you to use slow commands like "git status" without adding a delay every time the prompt needs to be printed.
E.g. the default prompt from prezto is quite light and responsive, but when inside a git repo adds the info on the right side (shows when you have commits ahead/behind the remote branch, stashes, modified/deleted/added/staged files, etc) when that becomes available.
Didn't look like any of the example themes on ohmyposh.dev had the $RPROMPT stuff, which I guess would be difficult support for a cross-shell theming engine.