Yes— all the Trackside does is modify power from another source, so you’d need a power supply still. I haven’t used the G Scale Graphics no frills units, but if I were starting over, that’s the one I would buy. That’s because a lot of the capabilities that you’re paying for in e.g., the USA trains power supply, are now covered by the remote (independent of any reliability issues).
One thing to be careful about is that, as far as I can tell, G scale graphics sells two versions of the remote, one for battery power and one for track power. It seems like they use R/C to refer to battery power and track power to refer to power from the rails. So make sure you buy the right one!