How intervals estimate my vo2max?

i was wondering how intervals estimate my vo2max because i’m not 100% sure how accurate it is.

i used whoop until 1 month ago i cancelled my suscription and whoop estimation was around 52, now i check my coros app and it’s going around 62. i’m wearing right now a google fitbit but this wereable does not track my vo2max, and on intervals my vo2max is 57… as you can see, too many variability between gadgets

i have connected to intervals: coros, strava, and fitbit data

This is what and how is estimated by Intervals (on the Power page)

But that is not necessarily what is in the Wellness VO2max field, because that Wellness field can be filled by an external source.