I can't speak to historically, but my understanding is currently, in the US, dental coverage was excluded from a lot of "this is insane, not allowed" provisions

I can't speak to historically, but my understanding is currently, in the US, dental coverage was excluded from a lot of "this is insane, not allowed" provisions in the ACA as a compromise, so all the fun things you loved seeing go away in health insurance like lifetime maximums on coverage are still around.