Lockable windows / escape route

But I can hardly imagine that the lockable handle would help. Probably good fittings plus pins and good roller shutters that cannot be pushed up will help more.

The first attack vector is prying. It happens quickly and quite quietly. Pins, pins, pins

If that doesn't work, wire is pushed through the seal or simply the frame is drilled through and then wire is pushed through to operate the handle (there is a nice video about this on YouTube). And only lockable handles help against that (nothing else).

Breaking the glass is more difficult. Especially with triple glazing or with an anti-burglary layer inside.

But even such windows are not really immune to drilling.

In the past, it was said that outdoor sockets should not be left powered.

Nowadays, with current battery technology, this is no longer an obstacle.