I have been experiencing the same issue the past couple of days. Xcode 16.2 is causing serious memory issues on my M3 Pro (36GB RAM). I only have 3 simulators installed (iPhone 16, 16 Plus, and 16 Pro all with iOS 18.3.1). Memory usage spikes over 20GB during build/run, and I've even seen it reach 62GB, leading to multiple system restarts.