In iOS 11, those same toggles are there, but they function differently: Instead of actually turning off the Bluetooth and Wi-Fi radios, they simply disconnect you from devices and networks. The radios stay on.
Apple isn’t likely to issue a fix for this unless there’s sufficient user outcry, but it isn’t a bug; it’s by design, according to this Apple support document.
What’s the purpose behind this new “feature”? As explained in that document, “In iOS 11 and later, when you toggle the Wi-Fi or Bluetooth buttons in Control Center, your device will immediately disconnect from Wi-Fi and Bluetooth accessories. Both Wi-Fi and Bluetooth will continue to be available.”
Why? So you can keep using “important” features and devices like AirDrop, AirPlay, the Apple Pencil, and the Apple Watch.
Here’s where it gets really weird: If you deactivate Bluetooth and/or Wi-Fi via Control Center, both will reactivate automatically starting at 5 a.m., or if you restart your device. And Wi-Fi reactivates if you walk or drive to a new location.
I suspect most folks toggle these radios off for security reasons and/or to extend battery life. Unfortunately, Control Center no longer allows you to turn off Bluetooth or Wi-Fi.
To do that, you’ll need to go into Settings, just like in the days before Control Center.
For Bluetooth: Settings > Bluetooth > Off
For Wi-Fi: Settings > Wi-Fi > Off