That's nowhere close to my experience. Things that steal focus constantly: 1password losing SSO token, UAC for an application's backup, 3CX call coming in, ever

That's nowhere close to my experience. Things that steal focus constantly: 1password losing SSO token, UAC for an application's backup, 3CX call coming in, every random thing in vscode, ... It's not something windows does or can disallow. You just focus the window in the code and that's it.