You can perfectly disable or delete Edge and Cortana and anything else if you wish.
How do i uninstall Microsoft Edge and Cortana
Go to C:\Windows\SystemApps
One of the folders in SystemApps refers to Edge and another refers to Cortana.
Read carefully the folder names and there will be no doubt.
Take ownership of the folders and grant yourselves full control
I will show you this for one folder
Elevated CMD prompt
takeown /f C:\Windows\SystemApps\Microsoft.MicrosoftEdge_8wekyb3d8bbwe
Enter
icacls C:\Windows\SystemApps\Microsoft.MicrosoftEdge_8wekyb3d8bbwe /grant administrators:f
Enter
Double-click the folder (open it) to see all the files
What we are looking for are Applications NOT Apllication Extensions
Inside the Edge folder you will find two applications that make Edge work.
MicrosoftEdge.exe and MicrosoftEdgeCP.exe
If you want to you have the full permission to delete these. But, JIC you want to use them afterwards . . .
Rename those files as .old (instead of the .exe) If you want to go back simply rename them back to .exe
Do the same procedure with the Cortana folder