Does 32GB of RAM help with stuttering in simulation games like Cities: Skylines or Flight Simulator?

Yes, but not for raw FPS. Simulation games like Cities: Skylines and MSFS care more about RAM than GPU. More RAM prevents stuttering by avoiding mid-game asset dumps to your hard drive. Cities: Skylines with mods easily eats 20GB+, and 16GB will crash or stutter. MSFS pushes past 16GB with add-ons. You won’t get +20 FPS, but your FPS will feel more consistent and freezes will go away.