Any early exit classifies you as last amongst the drivers still running when you exited. There's no "but it wasn't me" exemption because there's no obvious way for the lobby server to tell the difference between a console that's stopped communicating by a deliberate act (yanking the network cable), by a local error (power/internet failure), or by a wider issue. After all, pulling a network cable out also generates an error code.
You can minimise the chances of non-deliberate issues if you run through the advice in the Connection Issues thread:
Gran Turismo 7, it seems, follows in the fine traditions of GT Sport, GT6, GT5, and even GT5P in being a bit sensitive to network environments. A connection that's fine one day (or hour) might be ropey the next, and while there's a lot of things that might be out of your control, the best way to improve your experience is to make sure the bits that you can control are as good as they can be.
You don't need much technical knowledge at all to optimise your own network environment and make it as stable and friendly as possible. Here's a quick guide to doing so which will resolve many...