Not too long ago, Google started testing a new in-app browser for its Search app. It looks pretty reminiscent of the experience in the iOS app, with a similar loading animation when you open websites. The problem with this implementation is that in contrast to the Chrome custom tabs of old, the new browser is completely separate, meaning no shared history, bookmarks, or logins. Despite these disadvantages, Google seems to be willing to keep pushing its new in-app browser, as it has just gained its own Safe Browsing toggle and site settings options revolving around cookies and permissions.
Google introduced Chrome custom tabs five years ago, and most apps use them these days. Instead of creating their own custom browsers, developers can just hand over websites to a Chrome tab without the added bulk of a regular browser interface. The advantage is that devs don't have to spend resources on creating their own webview implementations and that users can quickly open these custom tabs in proper Chrome without reloading or losing their scroll position. It's a great system. But Google wouldn't be Google if it stuck with a great system (looking at you, YouTube Music).