According to liberal economics, aren't green cards more productive than H1-Bs?

It's a tenet that economies with labor mobility do better than economies without labor mobility.

So, it feels distressingly incompetent of leaders like Elon Musk to push the idea that reduced labor mobility is better for our economy than free labor mobility.

Advice to favor H1-B visas over expedited green cards to the real best and brightest seems uneducated, untrustworthy and myopic at best.