> Not only is that unconstitutional
While I do study relevant US laws as required in my job (requiring familiarity with how law operates in countries where we operate), I am not an American, but I do understand certain things with regards to the US constitution and relevant case laws.
The Congress originally meets only for a few months' time, usually less than 6 months. This is due to the reality of the time, where travel is slow and representatives only receive a comparable salary to most people. Thus, it is exactly empowered to delegate certain powers to the executive branch. As someone mentioned, the administrative law is a cornerstone law and yet it delegates many powers to the executive branch.
In fact, said law and many, many, many similar (federal) laws have been upheld constitutional in the Supreme Court. There are certain powers that only Congress can do, and cannot be delegated to the executive branch, but it is clearly laid out in the constitution what those are (notably spending). Now I said federal because in certain states, the legislature can only delegate in very narrow situations (usually only in cases where lives would be in danger or in the protection of properties and where a need of immediate response is demonstrated).
So I'm confused why are you saying that is unconstitutional, in fact American history shows a very different answer. If you think that should be not allowed, you're entitled to your own opinion. However unless I read it incorrectly, the constitution, even considering the various amendments, is unfortunately not aligned with your opinion.