I have found it very helpful for finding voices pretty far to the left. I also have found it very helpful for finding voices among marginalized communities, specifically indigenous folks, black women, anarchists, and queer folks- especially making fairly rational, well informed critiques of the US. And especially as that relates to things like Palestine or the Democrats failures in marketing Harri.
I can get a lot of that kind of content through other channels- there are plenty of podcasts out there.
However, the TT algo surfaces these things quite quickly and satisfactorally for me.
I can see how that really is a threat to US powers. I have a pretty good understanding of the various US oppressive actions against subversives, including the all-out war to demonize folks starting with anarchists/trade unionists/communists in the late 1800s to the use of COINTELPRO against folks like the black panthers, AIM, and the anti-war movement.
So from my standpoint, as someone who has gotten legitiamte "free-speech" value from the app, this move seems like just another step in a long history of US repression of political dissent.
If you start from the assumption that everyone who has different politics than you has been brainwashed or manipulated into that differing position, then sure TT seems like a great tool to do that. But if you think that it really takes immense amounts of capital and effort to get people to "form" opinions, you might take the position that the effort could only be done by folks who, say, have control of the "history" curriculum in Texas public schools ot, for instance, the power to have their press releases uncritically published by the New York Times.
Anyhow.
It will be interesting to see the US set up its own version of the Great Firewall, I guess.