>>519012962 (OP)
They didn't become biggest country in the world by being "bad at war". However their strategy is based on assumtion of unlimited resources (both human and material), which is no longer viable in case of modern world (low fertility) and even Russian Federation itself.
Strategically, Russia fights 19th century war in 21st century. Kind of why on tactical level war in Ukraine looks like WW1 (with drones instead of snipers).
However African countries still are sending their young officers to study in Russian military academies, instead of Western countries. That's because in their countries these tactics still are viable (as "air superiority" is absolutely alien concept to them).
That's because Russia is by it's philosophy, economy and politics Sub-Saharan country, who only inherited nukes from USSR.