I previously used ZPlug to manage zsh plugins, which added a noticeable latency for each terminal I opened.

z-shell/zi allows you to load plugins async very easily so my terminal feels snappy again. It is compatible with ohmyzsh, presto, zplug, etc; migration is a breeze.

Note: It is a fork of zinit, which was deleted by the author for unknown reasons. There is another repo, zdharma-continuum/zinit, which attempts to preserve/maintain zinit exactly how it was. z-shell/zi has less stars than that repo but much more activity.