Determined people may seek out independent online sources if they can digest that everything they've been told is a lie, but that's an insignificant fraction of the whole population and their activism is mercilessly crushed by security services. The critical majority remains unaware of what the whole world has seen on front pages for the past several weeks and instead lives in a parallel reality where the widely reported bombing of Mariupol's hospital didn't happen, or if it did, they were all Nazis and crisis actors. It's Alex Jones and InfoWars adopted as state religion. Insane.
People often believe what they want to believe. Repression of the press is not helpful. But it isn't hard to find the truth in Russia. You can find whatever truth you want to find.
All in all, thousands of Russian service members have died, but Russian representatives refuse to collect bodies from Ukrainian authorities for proper burial. Relatives are kept in the dark. Many will receive a letter months from now saying that their father/husband/son died in undefined military exercise. Those relatives who speak up get a visit from security service intimidating them into shutting up.
It's a total nightmare. There'd be a violent revolution the next day if Russian TV showed truth for one evening: orthodox churches burning, entire towns razed to ground, kids getting limbs blown off from cluster munitions dropped onto residential areas, all kinds of unimaginable suffering.
The scale of this is such that there's no way to conceal truth for an extended period of time. It will lead to implosion of Russian society just like the Afghan war did in the 1980s.