Wow, what a reminder. When we moved into our house 6 years ago, we followed the advice from several authors, and just ignored the base dirt, laid down cardboard, and built up layers of
compost, hay, straw, manure, etc. When we had to move those beds two years ago to build our greenhouse, the ground under the beds still looked and felt like concrete. Three years of gardening and watering hadn't even started to penetrate the hard subsoil.
So yes, I now know that we have to loosen the ground, or dig out a sunken bed, before we can plant anything and expect it to grow.