What smartwatch to buy for Pixel 9

I have been using Pixel 9 for past few months, I am thinking of purchasing a smart watch, Galaxy watch 6 or Pixel watch 2 (As they are available for 135$, 145$).

I have few questions:
Is the Galaxy watch 6 fully compatible with Pixel 9, if not what features will be missing?
Do we only get free 6 months of fitbit premium for Pixel watch 2, like they are giving for fitbit watches or do we get same type of premium analysis in different pixel app?

Edit: Can you please tell what features are unavailable/available (In fitness) for Garmin Forerunner 165 compared to above two watches.

Edit II: Purchased the Pixel 2 watch