There are many steps you can take to keep prying eyes or "hackers" out of your mobile device. Your tactics should not stop at simply increasing the security at the lockscreen level, that only protects your device from unauthorized logins in the event your device is stolen or some passerby wants to get in. What about all the data you send/receive on the device?
Don't use clear text messaging - SMS/MMS messaging in particular, as anyone at the cell phone company can read those...as well as law enforcement if they obtain a court order to dig up your text records. Only use messaging with end-to-end encryption...WhatsApp, Viber, Line, Signal private messenger, just to name a few. Enable "Lockdown" mode (when you hold down the power button, lockdown mode will prevent anyone from logging in unless they know your PIN or have your fingerprints), make use of Samsung's "Secure folder" app, and make sure that "Strong protection" is enabled within Settings > Biometrics and security > Other security settings > Strong protection (set to ON). That will encrypt any data stored internally on your S10. Of course, you can also choose to encrypt your SD card...keep in mind however if your S10 goes south any contents on that SD card will not be readable by any other devices, or a PC for that matter.
There are many steps you can and should take...be aware that sending/receiving data on your device may not always be encrypted. Avoid storing any sensitive information on your S10, in general. Phone calls are definitely NOT secure...the cell phone company keeps logs of every call you make, the NSA stores metadata from phone calls and text messages. Presume you're always being watched somehow.
If you've found my post to be helpful, please like the post. If my response helped resolve your issue, please press the "✓ Accept as Solution" button. Thanks!