I had one of the radioshack models in the 1980's as well. It was really helpful for learning basic circuits, but while it had a number of more advanced circuits, including three of four AM radio receivers, and a transmitter or two, I never really learned anything from those circuits despite reading the book a half dozen times. Looking at the 150 in one manual, the first transistor circuit is a basic small signal amplifier with the base connected to a coil. And now with a formal EE/CpE education, I can understand how/why it works and the biasing resistors, but I'm just as convinced that the book is largely useless except as a toy beyond the first dozen or two circuits because it doesn't do anything to explain the hows and whys of the circuits.

The modern equivalent of course are Snap Circuits https://elenco.com/snapcircuits/ but having purchased one of the larger kits for my kids a couple years back I think they suffer from the same basic problem. Sure telling 10 year old me about BJT biasing might have been a bit much, but I really think it should have been included in some kind of side note even if it doesn't sink in the first time.

PS: Actually thinking back on it, these spring board ones are probably better from the perspective that a blown component was easy to replace simply by pulling out the cardboard flipping it over and disconnecting the component from the springs underside.