Why would no one regulate it? Right, because both political parties are spamming as well. At the height of the presidential campaign I got 52 emails from republicans and 47 from democrats and they are full of dark patterns and manipulative language on both sides. It’s insane.
That particular loophole drives me up a wall. I routinely get upwards of a dozen political emails a day simply because I sent $20 to my district's US Representative once and only once.
I understand why things like ActBlue exist to centralize this kind of stuff in terms of contributions, but the comms side of things is still completely backwards.