Which do you think is more accurate? Apple Watch or Garmin?

I always found my VO2 Max higher and heart rate lower on Garmin devices compared to an Apple Watch.

Up until this year I was using an Apple Watch 6 and a Garmin Venu (2019) and I always believed that the Apple Watch is more accurate since it’s newer. Anyway this year I got a Garmin Epix 2 and an Apple Watch Ultra 2. Still the same, VO2 Max is higher and heart rate is lower on Garmin. Discrepancy is big too on Apple Watch it says my VO2 Max is below average while on Garmin it says I’m top 25% of my age bracket. Who to believe?