TW doesn't have any munitions that can remotely breach gravity dam like three gorges, i.e. bunker buster, which even if they did, they wouldn't have survivable platform to deliver it (strategic bombers, too heavy for TEL). US MOP tier 30000kg penetrator munitions isn't designed to crack three gorges, TW missile inventory are like 1500kg, at most they'll inflict scabbing or break exposed components like power infra, lock gates, which is not nothing, but not remotely compromise structural integrity of dam. This not to mention TW missile trajectory is geographically constrained and overflies the densest IADS environments on earth, assuming their TELs are survivable in the first place. They're much better off trying to threaten PRC coastal nuclear, but either way gets them the Gaza treatment.