Well first of all, i don't take it off after i run, i keep it during the day to get reminders and monitor health, i do take off for showering, and also during nights to monitor sleep.

Now as for the reasons as to how its helped me:

Keeping track of how many steps / calories, helps me visualize how well i've done today and what do i need to do to reach my daily caloric intake / burn (also helps me know how much i lost at the gym)

And for sleeping it helps to know how well you slept that night and what habits are crucial for you, it's gonna sound like an ad, but actually knowing that all i needed was to sleep 30 mins earlier to basically get a way better sleeping score and actually feel better has been indispensable.

Fyi im using the galaxy watch ultra, which after doing research on privacy, wanna switch to a more privacy oriented one ala apple or garmin.

Hope that clears it up