Apple forgot to mention Safari not being open source but rather tied to a proprietary platform not to mention Safari on mobile kept in a short leash to protect the AppStore.
How does one add a custom search engine to Safari? Even Google’s Chrome allows you to in Settings.
There's a "Search" tab in the settings. Although it doesn't seem like you can add Startpage for example or whatever else search engine. it only has Google, Bing, Yahoo and DDG.
I would like to add SearXNG or Kagi without installing an extension, like I can with any Chrome-based browser.