Russia's Far East is basically colonies that never decolonized. Most of Russia is situated in its Europe, and its hinterlands have notable density only along roughly the region of the Trans-Siberian Railroad once you get past around the Irtysh River (western tributary of the Ob). Even past Lake Baikal, Vladivostok, Khabarovsk, and Yakutsk are virtually the only cities.

Vladivostok was developed heavily, as Russia's only ice-free ocean port, but most of the rest of that region is far too sparsely populated. It's telling that, in modern times, Russia is quite paranoid that China is planning an invasion and takeover of that area.

Because the Pacific coast of Russia is thousands of land miles, and even more thousands of sea miles, from the places Russia wants to be able to influence. Having naval bases there doesn't really help them project naval force in Europe and the Middle East.