In the case of the Russians the corvettes are disproportionately important because they are one of the few vessels they have which can traverse their canal system. They can move them from the Caspian to the Black Sea to the Baltic, etc without going over the Mediterranean or any of the other bodies of water controlled by NATO. They are highly mobile platforms with long distance surface strike capabilities. They amply demonstrated that by hitting targets in Syria from the Caspian Sea with those ships.
China also has navigable rivers but strategically they are important in different ways and they aren't connected like that. Anyway other than Russia and a couple of other countries which have which per capita income but small displacement navies like Norway it's not common to spend so lavishly on corvettes.
I mean just look at this.
As many naval strike missiles as an LCS with one twentieth the displacement. Plus a gun that's higher caliber than the one in the LCS.
The Chinese have the Type 22 with a similar mission profile.