The Qt wallet is a more familiar desktop application. Instead of just commmand line text, users see a Graphical User Interface (GUI) that allows the user to navigate visually and click a few buttons instead of writing out all the commands in Linux.
Eventually, the Electron app will fully replace Qt wallet. At the moment, however, Electron is not a fully mature product. The Qt performs some functions better; and there are some that only the Electron can handle.
The Qt wallet is created using the standard Qt cross-platform application framework, which enables development of a feature rich Graphical User Interface for every major OS. As a widely supported framework for cryptocurrency wallets, it is powerful and far easier to use for most users than the command line.
QT wallet does not support any betting features. This was removed on the introduction of the Electron App
The Qt is the tool you need for an advanced set of features called "coin control." All funds credited to your wallet are the "unspent transaction outputs" (UTXOs) — the portion of the WGR that you got when someone else sent you WGR, but that you haven't spent. In cryptocureny, each transaction is separately tracked. Coin control allows users fine grained control over which UTXOs (which source of funds) they'll use for a given transaction. When you don't use coin control, the wallet chooses for you.
Only the Qt wallet supports spending zWGR to WGR. (Only Version 2 zWGR is currently supported.)
The Electron app has rudimentary masternode functions. Complete masternode functionality is under active development. Currently the daemon and the Qt offer the best set of tools to manage and monitor masternodes.