FWIW apps can use a SafariWebView IIRC to basically pass off a link to a separate Safari instance that can use autofill, content blockers, Javascript JIT, etc. but which the app doesn't have access to.

Meanwhile a WebView will show whatever HTML you throw at it, but it won't do any of that other fun stuff because the app that created it can access and manipulate the content (e.g. stealing your passwords) and the OS doesn't know if content filtering is relevant in that webview (since it's just the "show some HTML in a browser-type view" control and maybe it's important to see everything as-is). Being able to access the WebView also means the app can watch where you browse, what URLs, etc. so it can see what you're looking at even once you leave the page it opened to.

So yeah, apps can have a user-friendly experience; Telegram for the longest time used a SafariWebView so that everything was nice and neat. Then they decided to change their UI to a regular WebView and suddenly everything was full of trash again and I had to set it to "open in Safari" instead.