No, again, I don't understand where commenters are getting this idea from. The ruling does not require laws to be unambiguous. It only changes who is responsible for resolving ambiguity (changes it back). The entire system will do about as much work as it was doing before. At a stretch, you could say that maybe some funding would need to be reallocated from regulators to the courts, but one would hope that "cost of interpreting ambiguous laws" is not a meaningfully large line item in the US government budget.

Now leaving the specific judgement aside for a second, IMHO - not worth much as an outsider - Congress certainly should write more precise laws and maybe hire more aides to help them do that. All governments could do better on that front. Clear law is worth its weight in gold for creating a stable and prosperous society because when people know what they can and cannot do it's less risk to create new companies, less risk to create new products, and less time is spent in courtrooms arguing disputes caused by ambiguity. A lot of people commenting on this thread seem to fear a general breakdown if lawmakers are required to do a better job of writing law, but my personal experience of regulation (limited but not zero) has been that laws that have gone via a parliament or Congress are already higher quality than administratively issued regulations. The idea that the former are written by incompetents and the latter by experts is an intuitive one, but doesn't seem to be borne out in practice.

Also, as a general aside, I think Americans should appreciate Congress more than they do. It's popular to take a dump on them but if you compare to other governments around the world US law is fairly high quality. A big part of the success of the US economy and tech industry is related to what Congress does and doesn't do. For example the DMCA was unpopular when it passed but it laid the foundation for the dominance of Silicon Valley today. Apparently most Americans like their own Congressman/woman even whilst feeling the institution itself does a bad job, but this may just reflect the fact that America is very large and diverse, so inevitably a talking shop where people from different parts spend all day disagreeing with each other will seem dysfunctional.

I think you are missing the big picture. This ruling is setting the stage for a new regulatory regime. The lower courts see where this Supreme Court is going and they are going to overturn any regulatory ruling that has any semblance of ambiguity in the underlying law. What matters is the direction the court is going and what it is signaling with this ruling.

By the way, requirement of minimising ambiguity, and explicit limitation of delegation are not specific to the US. High courts of many other countries enforce this very standard.

What other countries do is not something I care about as far as SCOTUS goes. We don’t have parliamentary system that most other countries have and rewriting 40 years of legislation in the U.S. is lot harder to do in than in most other countries.

This ruling doesn't say courts have to overturn decisions based in ambiguous law, it says the courts have to make up their own mind about the decision. That decision may also be that they agree with the agency interpretation and choosing to uphold it.

The lower courts see where the Supreme Court is heading and they will rule accordingly. I could be wrong. In a few years I think you will see that I’m right.