When the root finds the correct soil
It is indeed difficult to predict where an unattached root may find a comfortable soil as solid long-term ground for support whilst growing.
No matter how much independent yolk the root may have to sustain an equitably healthy growth, the need for support in turbulent times carries no less a weight. Prodding and poking through various types of soil, to find a variant with compatible nutrients, it is either a great coincidence or a well-deserved fortune that one with well-matched moisture level and nutritional components may be discovered.
What next for the root?
To ascertain if the soil is not catering to other roots.