Yup, you are definitely too stupid to understand the strategic implications of China's military constructions.
You're right, a lot can happen in the future. China's goal is to first built civilian infrastructure so it can hold workers so it can move onto build military facilities. Militarising those islands is the primary goal of China so China can station its air defences and PLAAF fighters and bombers to extend China's military reach in the SCS. It will be like Hainan island. That's the goal of China and the US knows it. Unless the US can stop China's construction by destroying it now, these patrols do nothing from China extending its military reach in the very near future (2 years max).
China can station its current and future air assets such as bombers, fighters, transport which solves the main problem of dominating the SCS. China no longer needs to deploy its military assets from the mainland itself but now from these islands to escort foreign threats.
All the US can do is patrols, which doesn't stop China from militarising those islands and achieving its strategic objective.
Once China has stationed all its weapons on those islands, it becomes impossible for the US to destroy them as that will be deemed an unprovoked military strike on China and result in a war. The US don't have the balls to go to war with China. China has checkmated the US.