I am implementing fallback chrome custom tabs

I was referring to github sample has some custom fallback implementation. I didn't get why it is required.

I did following for handling fallback and is working fine.

  try {
        CustomTabsIntent.Builder builder = new CustomTabsIntent.Builder();
        builder.setToolbarColor(ContextCompat.getColor(context, R.color.appthemecolor));
        CustomTabsIntent customTabsIntent = builder.build();
        customTabsIntent.launchUrl(context, Uri.parse(url));
    } catch (ActivityNotFoundException e) {
        e.printStackTrace();
        Intent intent = new Intent(context, WebviewActivity.class);
        intent.putExtra(WebviewActivity.EXTRA_URL, url);
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TOP);
        context.startActivity(intent);
    }

Any idea why such complex implementation is required for handling fallback?

using following version of support librarycompile 'com.android.support:customtabs:25.3.1'