How long China's older destroyers remain worth upgrading

Can China standardize and upgrade its older destroyers enough to approach Type 052D capability?

Some Type 052C and 051C ships can remain useful, but older classes face diminishing returns from age, logistics, and limited upgrade potential.

Upgrading older destroyers lets the navy retain useful hulls while assigning newer ships to its expanding distant deployments. The Type 052C is considered a plausible modernization candidate, and the Type 051C is also regarded as upgradeable and relatively young, with construction completed in 2007. Earlier generations offer less room for useful improvement. Shenzhen, the Type 051B, is discussed as a surviving older ship whose remaining life is uncertain. Even upgradeable classes eventually face an economic limit when there are only a few ships to support. Maintenance, logistics, and cost can favor the newer classes built in much larger numbers.