Continue is the wrong word. Nothing is done by legislation or these companies themselves to properly regulate these platforms.
There is also nothing preventing foreign influence on U.S.-based company platforms, which is already happening, and has been happening, unchecked.
I have used WeChat daily for over three years. There is not a single instance in which I have been unduly influenced. I use it to message, video chat, and pay for things. That simply is not true for YouTube, Twitter, Google, Apple, etc. I can't even go to YouTube without having unremovable, unhidable ads for Trump. We also have a situation where the sitting president has rented out the YouTube homepage for an entire week prior to the election. It's naivety, and frankly delusional, to think the U.S. is somehow at threat by WeChat and not the multitude of sly behavior going on with U.S.-based companies.
U.S.-based companies and culture have long been driven by highly concentrated special interest groups, from Hollywood to Wall Street to Silicon Valley, and all of this amounts to undue influence and control upon the American people, who have been manipulated into playing the game.
It is much easier to enforce laws on a US-based company than a foreign one.