I am curious since it appears you are Canadian, what reform would you propose? The LMIA system in Canada faces similar issues but for a shorter period since immigrants with a high enough score on their application can secure PR within around 2 years. During those two years Canadian employers have similar leverage over immigrant employees. However under the American H1b system if you’re terminated, you have up 60 days to leave which is often not enough time to secure a new sponsor. Under the Canadian LMIA system you have 90 days and can potentially apply for a temporary visitors extension which allows immigrants and their families a better shot at staying. This delverages the employer to a degree.

There are several different aspects of policy that can be tweaked but the employer leverage is really a tough one to eliminate. Though it can certainly be cushioned by removing barriers to PR and offering a longer grace period in the event of termination as Canada has.