The most simple way to answer would be:

We don`t have any accents (or dialects) in Russian.

N.b. I travelled.
Yes, in the biggest country.
With 9 time zones...

But that is how differently languages develop due to historical reasons. I lived in 9-million Sweden, with differences on the South (Skånsk dialect) , Stockholm, North... Nothing like that in Russia, same speech from Kaliningrad to Vladivostok, from Murmansk to Sochi. Quite a comparison, huh?

Of course, there are some exceptions which only prove the rule