VO2 Max (again)

Using Watch S10 and Apple Health and getting absurdly low cardio fitness readings that are flatlined ~ 18, some research via AI reveals the algorithms in play are limited to GPS-driven activities (ie, distance based running, swimming, biking) and deliver caca from stationary cardio activity (treadmill, elliptical, stationary bike). This is a bummer and should probably be better disclosed by Apple Health. Anyone have a different experience - VO2 Max improvement over time as measured in non-moving cardio workouts?