I understand that Apple Watch does many things in the background. But when you’re comparing something like an Apple Watch vs Garmin Epix.
If they’re both turned on for hiking they are in theory using the same processing power, measurements. Apple Watch isn’t doing anything different. So why is it so poor? What else is it doing…
Like i said, garmin is great for working out. To answer your question however: there’s a giant library of third party apps called the app store which can provide you a similar experience. Adding third party apps is not even a thing on a garmin