Just like Texas abortion laws, this is not enforced against the US resident, it is against the service providers, which has allowed this framework to persist for 70 years.
The institutions that would want to operate these have the power to run massive advertising campaigns promoting them as the best place to earn money (with a bunch of quick disclaimers just like the various medical ads that people have gotten so used to now).
The people who would be preyed upon by this are not those with the education and experience to tell what's a sound investment and what's a bunch of bullshit, but precisely the opposite.
And though I know that there are many—perhaps you're among them, perhaps not—who would say "anyone who can fall for such a scheme deserves to lose their shirt", personally, I believe that we live in a society and we have a greater duty to care about each other than that.
In practice, it locks them out of scams.
It is horrendously irresponsible to enable practices that we can predict will, with very high probability, result in significantly greater ability for predatory and unscrupulous actors to take advantage of the public, especially if the purpose is merely to allow the wealthy—and it is only the wealthy who can genuinely take advantage of such things; the rest of us simply can't afford to take those risks—to try their hand at high-stakes gambling.
It is an overfitted system that has created more and more compliance in response to rare scams that occurred within the rules of their system anyway! If companies didnt find it too expensive to go public earlier nobody would be trying to have this conversation. People wouldnt be getting ripped off in massive SPAC deals because the target companies would be public already.
"regulated as a security" itself can mean 100 different things, and its not a nuanced enough take to know if a product can be offered at all, to whom it can be offered to, what disclosures are necessary if any, and more
They are expecting Coinbase to show them who is regulating them. If they don't do it, they must be sued.
Coinbase is promising a fixed 4% earning. If they are to be taken serious, 4% does not mean the risk of losing it all, like in a casino.