Russia has a lot of inland lakes, and has always defined its empire with non-negotiable geopolitical requirements for blue-water ports on all sides. The countries that pose a threat to those ports generally have a lot of vulnerable coastlines. Fly an ekranoplane empty to a staging area, fill it with a regiment, fly it in boost mode over any land obstacles, and you can rapidly drop significant troop numbers at any point on the coast without control over the body of water.
Larger ekranoplanes that can operate higher off the water are more useful as transports, and things plausibly get much bigger than the KM.
Russia has a lot of inland lakes, and has always defined its empire with non-negotiable geopolitical requirements for blue-water ports on all sides. The countries that pose a threat to those ports generally have a lot of vulnerable coastlines. Fly an ekranoplane empty to a staging area, fill it with a regiment, fly it in boost mode over any land obstacles, and you can rapidly drop significant troop numbers at any point on the coast without control over the body of water.
Larger ekranoplanes that can operate higher off the water are more useful as transports, and things plausibly get much bigger than the KM.