I wish I shared your optimism that the US would ever legislate anything even remotely approaching the DMA.
It seems to me that American culture is so entrenched in this (absurd, IMO) notion of "liberties" and "freedoms" ... which in practice only ever seem to apply to corporations with trillion dollar market caps.
The FTC has been chaired for years now by someone who wrote their thesis on the anti-competitive practices of $FB and $GOOG and whatever. And yet, despite her best intentions/efforts, the FTC under her leadership has proved to be utterly toothless time and again.
If they can't even stop M$ from gobbling up Activision/Blizz, how on earth would sweeping changes to how (digital) business is done in the US ever hope to succeed?