Plus, you didn't tell us what the "other phone" is. Same model? Same setup? Same amount of memory? Same signed in accounts?
Same CPU (that's very important)?
As mentioned, there are many things that run in the background on modern phones. Anything that keeps your notifications going - emails, Facebook, Twitter, Instagram, TikTok... I mean, I don't know what all you have running on your phone, but even the Google app and many of Samsung's background services will keep the cores in that CPU running constantly to some degree.
Also, has it upgraded to Android 11 yet?
Note that the A20e has the mediocre performing Exynos CPU.
If you are comparing it to another phone with the Qualcomm chip in the 600 series range or higher (especially with only 3 GB of ram), that Exynos chip isn't going to compare well at all.
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