I have never read or heard of anyone using desktop Safari due to a “limited appetite for browser customization”. In every context of every conversation I’ve witnessed where desktop Safari was mentioned, every participant was fully aware other browsers exist.

As an example, Safari is the only choice if you don’t want to give more marketshare to Chromium but also need to programatically control or retrieve information from your browser. Firefox has no AppleScript support, which disqualifies it immediately.