None. Those are private companies that do this. It's the same in Germany. I have a 7 euros/month unlimited calls cell plan but only 500 mb data, which is enough for me. I pay around 25 Euros month for Internet at home. It's fast enough for Steam/Streaming, I don't even know the speed because I stopped caring a while ago.

In Russia, 1gbps may be from $3 to $10 per month depending on the place, and it works as such at least throughout Russia maybe falling to 200-300mbps to far off places like the U.S.

In Lithuania, i paid 15 EUR a month for 500/500 and it worked perfectly too.

U.S. prices are super high - mostly a consequence of most people living in detached houses - long distances and high complexity of wiring. In Russia and Lithuania, most live in Soviet-style apartment blocks - high user density.

Nothing, those are private companies without subsidies