Yeah the price increase going from 16GB to 32GB is definitely reasonable, not too bad. Just checking Newegg looks like on average price delta is about 25-50% for double the capacity. But even still, skimming through benchmarks videos there seems to be no performance difference in any games. I don't see much point if there's no discernible difference for my use case. That's just me but yeah, I can see for future proofing might be worthwhile going with 32GB if you don't plan to upgrade for a long time.
Is this just your personal experience, or did you see articles/videos that did benchmarks showing this? Did you personally have the issue with 16GB, and when upgrading to 32GB the hitching went away?
I just played AC: Odyssey and it was smooth my whole playthrough. Didn't play the other games.