Whether real world or FSX, there are lots of places where VORs and NDBs are the main form of navigation - especially for landing. The FAA/NavCanada/etc. will get around to providing GPS approaches to every airport, but that will take a few years yet. For most of us in the flightsim world we only get to fly the big iron in the sims, and we generally don't try to fly a 777 into a backcountry airport. In the real world, those of us who are pilots generally own light aircraft that aren't equipped with the latest glass panels. It depends on your flying!
I will say that in the real world, the loss of GPS signal can be disorienting. I was only 20 miles back from the airport I trained at (in other words I should have the environs engraved into muscle memory!!) when I lost signal to both my portable and the panel-mount. I was being lazy and had not sett up the underlying beacons as a back-up (surely both GPSs won't go bad!) and had to start paying attention to ground references again. It took a few moments to get back in the game. Fortunately, it was a good weather day. I find I have better habits in the clouds where the magenta line is a confirmation, not a primary source. Perhaps flying in Alaska and northern Canada (parts of New Zealand and Australia?) would be different because of the sparseness of the ground-based navaids and the chances of rapidly changing weather in mountain areas.
Once you have the art of flying down pat, flying with reference to VORs/NDBs can be challenging - both in the real world and in simming.