I wore the Garmin Fenix 8 vs. Garmin Instinct 3 for two weeks — which is better?

I have a Garmin fenix and and the HR sensor is terrible. It routinely reads 40bpm off from my HR monitor. I definitely wouldn’t rely on this watch alone for training without a hr monitor. Other than that it’s great. I really like the Garmin connect app and all the info this watch and my bike computer provide.