Why didn't Russia expand its territory to the Far East and even occupy Siberia?

The reason why tsarist Russia has been expanding in the Far East instead of expanding to the south is mainly because tsarist Russia is afraid of the powerful Central Plains Empire in the south. You should know the strength of czarist Russia. In fact, it was not a first-class power in Europe at that time. It was not until Russia began its modernization reform that Russia gradually moved towards the road of becoming a powerful country.

Moreover, the main reason for Russia's expansion to the Far East is to find a seaport where it can go to sea. Because Russia was just an ordinary landlocked country with no coastline at that time, and Europe was in the period of great navigation, if Russia wants to become a world power, it must first become a maritime power. The main goal of Russia's outward expansion without a seaport is to seek a seaport. Therefore, after formulating such a basic national policy, Russia found that there are many seaports in the far east and the north. Moreover, because the seaports in the north and the Far East have ice ages, they are full of disadvantages compared with those in other powerful countries, but fortunately, these seaports are far from the inland, so Russia does not have many strong competitors there. Therefore, in order to reduce military risks, Russia chose to go north.

In fact, Russia once thought about developing to the south. He once conquered the lower reaches of the Volga River by himself. Then, after several bitter wars, Russia finally defeated Turkey, a powerful country at that time, and took control of the Caspian Sea and the Black Sea. But after the war, they found that the sea they got was just a saltwater lake. From here, you can only go to sea through the narrow strait, and you must first enter the strait of Gibraltar controlled by the British before you can enter the Atlantic Ocean.

This war reduced the number of times Russia tried to go south, and the seaports in the Far East and the North became Russia's primary targets. ?