As a half solution: You can create a Shortcut that turns of BT/Wi-Fi completely. You can then add that Shortcut to your home screen for easy access. That's what I do and it's way nicer than going to Settings, though I wish it was just in Control Center.
Go to the Shortcuts app that comes with the phone. You can create shortcuts to do just about anything, in this case you'd make one that sets WiFi to Off and sets Bluetooth to Off. Then that shortcut can be turned into an app icon that you can just press any time.
