> the claim "most of the companies registered in Delaware are not trying to dodge US federal regulations" strikes me as dubious.

Why would it? Choosing the state to incorporate in has very little to do with US federal regulations. If the US wants to come after your company for some reason, they file in federal court, and the state you're incorporated in is irrelevant.

When incorporating, you choose the state based on its business-related laws and how they might apply to your company. You choose based on the experience of their judicial system in handling business matters. You might choose because there are a ton of other businesses incorporated in that state, and that's created a lot of court cases and a lot of precedent that can give your own legal team more confidence in how different sorts of legal challenge might play out.

If you were trying to avoid US federal regulations, you might incorporate in Delaware for the simple reason that Delaware is a safe default, given how common it is for companies to incorporate there. Incorporating in an unusual state could raise an eyebrow here or there. But ultimately it's not going to matter all that much. And even if it's true that a federal-regulations-skirting company would have a measurable benefit to incorporating in Delaware, there's no reason to believe that lots of companies incorporated in Delaware are trying to skirt federal regulations. That's just an unfounded assertion.

As an aside, it's not true that every company wants to decrease its regulatory burden. Once a company gets large enough, lobbying for extra regulation can be a barrier to entry for possible competitors. Also consider that "reducing regulatory burden" doesn't necessarily mean doing something illegal. In the case of Polymarket, they probably are, but plenty of other companies find ways to reduce their regulatory compliance needs in perfectly legal ways.