There are too many "anti-vaxers" in Russia that don't trust any vaccine exist on the market.
At the same time, our government thinks about allowing tourists vaccinated by other than Sputnik-V (aka Gam-COVID-Vac) to pass Russia's borders. I'm waiting for Friday to complete my vaccine cycle. I planned to vaccinate with a single-component Sputnik Lite vaccine, but it was not available to use in early July (and has less efficiency), so I went for dual-component Sputnik V.