I encourage you to read up on the J.E. Hoover and J. McCarthy on how much the US First Amendment is worth. Or maybe try running a pro ISIS webserver in the US, see how quickly you have the FBI knocking on your door. Let's not even talk about DCMA takedowns etc..
The US ranks lower than Germany in the FH and RWB freedom of the press indices [1], which while not quite the same is highly related to freedom of speech.
The First Amendment is stronger than any equivalent rule in any other modern country that I'm aware of. The fact that it's been undermined repeatedly, both in the past and the present (due to the recent wave of authoritarianism that has been sweeping US politics, which can be seen clearly on HN itself), doesn't have any bearing on its relative ranking - so, it can suck (or just be a little suboptimal), but still be better than everything else.
Moreover, how is DMCA relevant? Copyrighted works are outside the bounds of free speech.
Wait, what? How does the fact that it's undermined not have an impact on how useful a US right is to me?
DMCA, and in general the US legal system are extremely relevant to me as a user. If I have a theoretical right to free speech, but in practice any big US media company could kill it then I'm much better off in another country where maybe the theoretical right is 10% less but I can actually practically enjoy that right.
Those rankings just encode the political outlook of a certain leftist NGO.
In the USA, Neonazi publications are allowed, while in Germany they are illegal. Therefore, the US has a freer press than Germany. Freedom House would disagree, and they are simply wrong.
The US ranks lower than Germany in the FH and RWB freedom of the press indices [1], which while not quite the same is highly related to freedom of speech.
[1] https://en.wikipedia.org/wiki/Censorship_by_country