More worry about security updates, my s7 edge still on jan18 patch..
More people do financial transactions on phones, missing security is bad.
Going with note 9 means super inferior exynos and slow security patching.
https://www.wired.com/story/android-phones-hide-missed-security-updates-from-you/amp
From that website, Samsung is doing well at the cost of timings of the update. They barely missed any patches.
TBH, if you are worried about all these little things you are on the wrong ecosystem. Your device is very secure as long as you don't expose it outside of Google's official and authenticated systems. So No sideloading (You wouldn't know if the app has been modded) , avoid installing untrusted apps (Weird shady Chinese apps are the worst) and don't connect to an unsecured network.
Plus you using an Android device you are already constantly being tracked. Google knows your whereabouts almost all the time (Unless your device is out of battery). Even if you turn off Location history your location is still recorded and stored somewhere. Your browser and app activity as well all recorded and Google knows it all.
Think about it you are using a device whose operating system is controlled and designed by the world's largest advertiser whose entire business is selling targeted ads and for "free".
And you wonder why iOS devices are expensive..