Hello,
Thank you for reaching out to Microsoft Q&A. After reviewing your questions, here are the answers:
WebView2 re-installed after you uninstalled it because On Windows 11, the Evergreen WebView2 Runtime is included (inbox).
On most Windows 10 consumer devices, Microsoft may have delivered the Evergreen Runtime (see the “Delivering the Microsoft Edge WebView2 Runtime to Windows 10 Consumers” article).
Many apps that are built on WebView2 perform checks to re-install WebView2 when the app is installed or launched.
Enterprises can also push WebView2 to devices that they manage.
I hope this helps! If you have any further questions, please feel free to ask.