I miss a lot of functionality and usability from my old phone. The phone app on this one is almost a direct rip-off of the vastly inferior iOS phone app.
It was a two-step process to call someone previously, but now it's a three-step process. Whatsapp/Skype/Signal used to be integrated into the process as well, but now I have to manually open the contacts app to access that feature. Which makes it completely pointless to even have it. No longer can I call them directly using the phone app.
X1ZC power button doubled as a screenshot and switch-off menu. S20 delegates that to a swiping tab on the corner which is difficult to pull out depending on which app it is drawn over. Even there I can't take a quick full-screen screenshot without first expanding a square tool across the entire phone.
A lot of crufty apps cannot be disabled either, which is an extreme downgrade. For example Signal is my default SMS app, but I can't disable the messaging app. Very unfortunate.
WiFi calling and VoLTE are broken.
Battery life is poor even in power-saving modes.
One-handed operation is a mega pain in the bosom.
I never saw whatsapp integrated in my old Z3C, not sure what you were doing in your previous phone. I always used to call someone from whatsapp by opening the whatsapp app.
There's an option to swipe with palm to take screenshot or press volume down + power button to take screenshot. The square tool is meant only for taking screenshot of a part of the screen.
Lack of ability to disable a lot of default apps is a pain, but not as big of a pain as Xiaomi for sure. Still, Samsung should do better.
I have an option to enable VoLTE in my S8, still it doesn't work, pretty annoying for sure.
120Hz takes a big hit on battery life, moreover the compact S series always had above average battery life, not good one like many budget phones can even provide. I guess it should last a day with 4hrs or so of screen on time.
Lack of compact phones is a big problem for people like us. I plan to just change the battery of my S8, no phones worth upgrading to except for expensive ones or Apple.
I have a theory that Exynos phones degrade in battery life & performance faster than Snapdragon variants. I have an S835 S8, not Exynos one. It is working well, definitely runs slower than new OP phones & all if compared side by side.