Many pre-installed Android apps can not be easily removed within the phone app store. With a PC you can remove unwanted apps.
On phone, enable developer mode. Open the Settings app on phone and scroll down to About Phone, Software Info. Tap on the Build Number seven times to enable Developer Options.
On phone in Settings app, enable USB Debugging.
Plug the phone into PC with USB cable.
On MS Windows, download Google's adb tools from https://dl.google.com/android/repository/platform-tools-latest-windows.zip
Unzip the file.
Open MS Windows PowerShell.
In the PowerShell window, cd into the downloaded directories.
In the PowerShell window, run: ./adb devices
The phone device is listed with status "unauthorized". Phone can not yet be accessed from PC.
On the phone there should be a prompt to allow connection to PC. Press Allow.
In the PowerShell window, again run: ./adb devices
After running the next command to enter the shell, the remainder of commands in this example will be run within the shell. In the PowerShell window, run: ./adb shell
pm list packages
You may want to copy the list of packages to a text editor for review.
Let's remove the weather apps.
pm list packages | grep weather
acexlm:/ $ pm list packages | grep weather
package:com.lge.sizechangable.weather.platform
package:com.lge.sizechangable.weather.theme.optimus
package:com.lge.sizechangable.weather
Uninstall each entry:
pm uninstall -k --user 0 com.lge.sizechangable.weather.platform
pm uninstall -k --user 0 com.lge.sizechangable.weather.theme.optimus
pm uninstall -k --user 0 com.lge.sizechangable.weather
On the phone please refresh the list of apps. Notice the weather apps are listed as "Not installed".
Remove a few other apps. Notice the shell command "pm list packages" is used with flag "-f" instead of a pipe to "grep".
The older Google Duo app is "tachyon":
acexlm:/ $ pm list packages -f tachyon
package:/product/app/Duo/Duo.apk=com.google.android.apps.tachyon
acexlm:/ $ pm uninstall -k --user 0 com.google.android.apps.tachyon
Success
Remove Google Pay:
acexlm:/ $ pm list packages -f wallet
package:/system/app/GooglePay/GooglePay.apk=com.google.android.apps.walletnfcrel
acexlm:/ $ pm uninstall -k --user 0 com.google.android.apps.walletnfcrel
Success
Restart the phone and check for functionality.